. Earth Science News .

Sea cucumbers: Dissolving coral reefs?
by Staff Writers
Washington DC (SPX) Dec 30, 2011

They collected some of these sea cucumbers and placed them in aquaria to study the effect on sea water resulting from the sand and rubble transported through their gut system as part of their digestive process.

Coral reefs are extremely diverse ecosystems that support enormous biodiversity. But they are at risk. Carbon dioxide emissions are acidifying the ocean, threatening reefs and other marine organisms.

New research led by Carnegie's Kenneth Schneider analyzed the role of sea cucumbers in portions of the Great Barrier Reef and determined that their dietary process of dissolving calcium carbonate (CaCO3) from the surrounding reef accounts for about half of at the total nighttime dissolution for the reef. The work is published December 23 by the Journal of Geophysical Research.

Reefs are formed through the biological deposition of calcium carbonate (CaCO3). Many of the marine organisms living on and around a reef contribute to either its destruction or construction. Therefore it is crucial that the amount of calcium carbonate remain in balance. When this delicate balance is disrupted, the reef ceases to grow and its foundations can be weakened.

In order to fully understand a reef's ability to deposit carbonate and grow, it is necessary to understand the roles that the various elements of sea life play in this process. This is especially important because increased atmospheric carbon dioxide is predicted to decrease the amount of carbonate available due to acidification.

The research group set out to examine the role that sea cucumbers play in the reef environment.

Schneider's team included Carnegie's Ken Caldeira, as well as Jacob Silverman, of the Israeli Limnology and Oceanography Institute; Maria Byrne and Erika Woolsey, both of the University of Sydney and the latter also from James Cook University; and Hampus Eriksson of Stockholm University.

They studied the growth and dissolution of One Tree Reef, which surrounds One Tree Island in Australia's Great Barrier Reef. Focusing on an area of the reef known as "DK13", they found that sea cucumbers were abundant.

They collected some of these sea cucumbers and placed them in aquaria to study the effect on sea water resulting from the sand and rubble transported through their gut system as part of their digestive process.

As part of another ongoing study in this area, the team found that the coral reef was dissolving at night. They found that sea cucumbers play a crucial part in this process.

They live off the bits of organic matter in the carbonate sand and rubble that they ingest; in this process, their digestive systems produce acids that dissolve parts of these carbonate minerals.

The dissolved carbonate minerals are then released into the surrounding environment. The researchers found that these lowly organisms might be responsible for half of the CaCO3 of the reef observed at night.

The burning of coal, oil, and gas releases CO2 into the atmosphere, which is later absorbed by the ocean, causing the ocean to acidify. Ocean acidification is expected to slow reef growth. With slower reef growth, the dissolution of CaCO3 within the guts of sea cucumbers is expected to become even more important to the reef CaCO3 budget.

"Even though the sea cucumbers dissolve CaCO3 on the reef, in a lagoon such as the one at One Tree Reef, where there is limited seawater exchange with the surrounding ocean, they can be important in recycling of nutrients to support primary productivity. They also increase sea water buffer capacity to partially offset ocean acidification effects, helping to maintain the overall health of the coral reef," Schneider said.

"Although sea cucumbers may play a part in reef dissolution, they are also an important part of an incredible marine environment."

Related Links
Carnegie Institution of Washington
Water News - Science, Technology and Politics

Get Our Free Newsletters Via Email
Buy Advertising Editorial Enquiries


. Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Taiwanese seas threatened by overfishing
Taipei, Taiwan (UPI) Dec 29, 2011
Ocean ecology surrounding Taiwan is threatened by overfishing, a new report warns. The Taiwan Environmental Information Association report, which says the reduced presence of sea life shows that all isn't well with the local marine ecosystem, urges the government to designate protected marine areas. Data from the Taiwan's Fishery Agency indicate that the annual catch from coastal ... read more

Haiti commission recommends restoring army

New Year despair for Japan's nuclear refugees

Japan's nuclear safety panel received donations: report

Life In An Age Of Unnatural Disasters

Tablets, e-readers closing book on ink-and-paper era

Better turbine simulation software to yield better engines

Kindle sales on fire: Amazon

Harvard physicists demonstrate a new cooling technique for quantum gases

Taiwanese seas threatened by overfishing

Italian fisherman recovers lost boat after 700-km journey

Japan indicts Chinese skipper for illegal fishing

Sea cucumbers: Dissolving coral reefs?

Lockheed Martin Wins Major US Antarctic Program Support Contract

Glacial tap is open but the water will run dry

CryoSat ice satellite rides new waves

Season's greetings from the other extreme

New China food safety scandal widens to oil, peanuts

Latest China food safety scandal widens to oil

Toxin found in Chinese milk

China jails six over tainted pork

Cyclone hits India's southern coast, kills 33

India repairs damage after cyclone kills 42

42 people die in south India cyclone: report

New island forms in Red Sea off Yemen: NASA

25 held over Bissau 'coup plot', weapons cache seized

Coup scare points to power struggle in G.Bissau

Guinea Bissau says coup-plotter executed

Ivorian leadership faces conundrum with rowdy ex-rebels

Spectacular fireworks ring in New Year

How to break Murphy's Law And Live To Tell The Tale

Human skull study causes evolutionary headache

Malaysian 'lords of the jungle' cling to ancient ways


The content herein, unless otherwise known to be public domain, are Copyright 1995-2012 - Space Media Network. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement