Featured Research

from universities, journals, and other organizations

Acid oceans demand greater reef care

Date:
February 17, 2011
Source:
ARC Centre of Excellence in Coral Reef Studies
Summary:
The more humanity acidifies and warms the world's oceans with carbon emissions, the harder we will have to work to save our coral reefs. That's the blunt message from a major new study which finds that ocean acidification and global warming will combine with local impacts like overfishing and nutrient runoff to weaken the world's coral reefs right when they are struggling to survive.

Tropical coral reefs are under pressure from a suite of global and local stressors. In this article, Anthony and colleagues present a quantitative model for the resilience of benthic coral reef communities under combinations of ocean acidification, global warming, overfishing and nutrification. Projections for a high CO2 emission scenario alone can drive reefs from coral to macroalgal dominance, but such community phase shifts are likely to occur faster and more dramatically under herbivore overfishing and nutrient enrichment. Safeguarding coral reefs in the 21st century will require urgent solutions to the global carbon problem as well as strong management of local disturbances.
Credit: Photo courtesy of Jeff Maynard

The more humanity acidifies and warms the world's oceans with carbon emissions, the harder we will have to work to save our coral reefs.

That's the blunt message from a major new study by an international scientific team, which finds that ocean acidification and global warming will combine with local impacts like overfishing and nutrient runoff to weaken the world's coral reefs right when they are struggling to survive.

Modelling by a team led by Dr Ken Anthony of the ARC Centre of Excellence for Coral Reef Studies and The University of Queensland's Global Change Institute has found that reefs already overfished and affected by land runoff are likely to be more vulnerable to increasing CO2 in the atmosphere caused by the burning of fossil fuels.

Their study is the first to integrate global scale processes, such as warming and acidification, with the local factors overfishing and runoff, to predict the combined impact on coral reefs.

"As CO2 levels climb to 450-500 parts per million - as they are now expected to do by 2050 - how well we manage local impacts on reefs like fishing and runoff will become absolutely critical as to whether they survive as coral reefs, or are overtaken by algae that compete with corals for space on reefs," Dr Anthony says.

Warmer conditions cause periodic mass coral deaths by bleaching, while acidifying sea water - due to CO2 dissolving out of the atmosphere - weakens the corals by interfering with their ability to form their skeletons, making them more vulnerable to impact by storms. If the corals are also affected by heavy nutrient runoff from the land - which fertilizes the algae - and overfishing of parrot fishes and others that keep the reefs clear of weed, then corals can struggle to re-establish after a setback, he explains. "In those situations, the reef can become completely overgrown by algae."

The team's modelling, which they say is on the conservative side, has far-reaching implications for the preservation even of well-managed reefs such as Australia's Great Barrier Reef - and extremely serious implications for reefs in developing countries, where most reefs are located and where reefs face high levels of stress from human activities.

"Put simply, our model indicates that the more CO2 we humans liberate, the harder it will become for coral reefs, as we know them, to survive. This means they will need all the help they can get in the way of good management to prevent their being overgrown by sea weeds," he adds.

"Coral reefs in developing nations, where most of the world's reefs occur and overfishing and nutrification remain key concerns, are particularly vulnerable, highlighting the need to continue to build capacity amongst reef managers and governments in areas like SE Asia," the team warns in their report, which was recently published in the journal Global Change Biology.

"A failure to rapidly stabilize and reduce the concentration of CO2 in the Earth's atmosphere is likely to lead to significant loss of key (coral) framework builders such as Acropora, irrespective of the effectiveness of local management," the scientists conclude.

"However local reef management efforts to maintain high grazing fish populations and prevent runoff of silt, fertilisers and sewage from the land will play a critical role in maintaining coral resilience while CO2 concentrations are stabilized," they add.

The study, which is the first to quantify the relative importance of carbon emissions and local disturbances in compromising reef health, can be used to optimise future management practises of coral reefs. It makes clear that both policy changes on emissions and local management measures are required to secure a future for coral reefs.


Story Source:

The above story is based on materials provided by ARC Centre of Excellence in Coral Reef Studies. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kenneth R. N. Anthony, Jeffrey A. Maynard, Guillermo Diaz-Pulido, Peter J. Mumby, Paul A. Marshall, Long Cao, Ove Hoegh-Guldberg. Ocean acidification and warming will lower coral reef resilience. Global Change Biology, 2011; DOI: 10.1111/j.1365-2486.2010.02364.x

Cite This Page:

ARC Centre of Excellence in Coral Reef Studies. "Acid oceans demand greater reef care." ScienceDaily. ScienceDaily, 17 February 2011. <www.sciencedaily.com/releases/2011/02/110214102126.htm>.
ARC Centre of Excellence in Coral Reef Studies. (2011, February 17). Acid oceans demand greater reef care. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2011/02/110214102126.htm
ARC Centre of Excellence in Coral Reef Studies. "Acid oceans demand greater reef care." ScienceDaily. www.sciencedaily.com/releases/2011/02/110214102126.htm (accessed September 17, 2014).

Share This



More Earth & Climate News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Isolated N. Korea Asks For International Help With Volcano

Isolated N. Korea Asks For International Help With Volcano

Newsy (Sep. 16, 2014) Mount Paektu volcano in North Korea is showing signs of life and there's not much known about it. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

      Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins