Featured Research

from universities, journals, and other organizations

Increasing Carbon Dioxide Threatens Tropical Coral Reefs

Date:
April 2, 1999
Source:
National Center For Atmospheric Research (NCAR)
Summary:
Tropical coral reefs could be harmed by atmospheric carbon dioxide (CO2) entering the oceans; some reefs may already be declining. Joan Kleypas (National Center for Atmospheric Research) comments, "These findings represent some of the first evidence of a direct negative impact of increased CO2 on a marine ecosystem."

BOULDER--Tropical coral reefs could be directly threatened by thebuildup of atmospheric carbon dioxide (CO2) entering the oceans, andsome reefs may already be declining, say six scientists in a paperpublished in the April 2 issue of the journal Science. Writes leadauthor Joan Kleypas of the National Center for Atmospheric Research(NCAR), "We believe that these findings represent some of the firstevidence of a direct negative impact of increased CO2 on a marineecosystem." NCAR's primary sponsor is the National Science Foundation.

The team's findings apply primarily to coral reefs located in surfacewaters between 35 degrees north and 35 degrees south of the equator.However, the authors predict that reefs in greatest danger are thosewhere the production and destruction of calcium carbonate are closelybalanced. These include some higher-latitude reefs, such as those offBermuda; those in areas where colder, deeper waters rise to the surface,such as those off the Galapagos Islands; and many reefs already stressedby human activity.

A coral reef is the accumulation of calcium carbonate produced by thecorals and other calcium-secreting organisms, such as coralline algae.If calcium production declines, coral and algal skeletons will weakenand reef building may slow or stop. The reef then becomes morevulnerable to erosion. Ongoing calcium production depends on thesaturation state of calcium carbonate in surrounding surface waters.This saturation state declines as CO2 enters tropical surface waters.

Carbon dioxide is an important greenhouse gas produced by fossil-fueluse. For their study, the authors used future scenarios in which thepreindustrial level of CO2 doubles by the year 2065--considered amoderate projection by the Intergovernmental Panel on Climate Change, aninternational group of 2,500 scientists. As the gas builds up in theatmosphere, the tropical sea surface takes it up at a proportional rate.Scientists have so far focused on CO2 storage in the ocean. This is oneof the first studies to examine how CO2 increases may affect thechemistry and biology of ocean ecosystems.

As CO2 dissolves, it produces an acid that lowers the seawater pH. Theinteraction of carbon dioxide with calcium carbonate in seawaterdecreases the level of calcium carbonate saturation. Given the rapidrise in CO2 levels expected over the coming decades, the authors projectthat by the year 2065, the interaction of CO2 with seawater will havereduced calcium carbonate saturation in tropical surface waters by 30%relative to preindustrial levels.

The findings are based on ocean carbon data and computer models, and onlaboratory experiments which show that coral and algal calcificationdeclines as the saturation state declines. The coral reefs themselveshave not been studied in situ. "Our work is somewhat speculative," saysKleypas. "We need more studies at the ecosystem level. If the laboratoryresults bear out in the oceans, I think many species of coral reefscould be vulnerable."

The buildup of CO2 may also warm ocean surface temperatures. Althoughwarmer sea-surface temperatures are being blamed for the recent increasein coral bleachings worldwide, some feel that this warming could be aboon for reefs in chilly waters. However, says Kleypas, if the calciumcarbonate saturation rate is as important as water temperature in reefbuilding, warmer waters won't save higher-latitude reefs.

NCAR is managed by the University Corporation for Atmospheric Research,a consortium of more than 60 universities offering Ph.D.s in theatmospheric and related sciences.

-The End-

UCAR and NCAR news: http://www.ucar.edu/publications/newsreleases/1999

Via e-mail: send name, affiliation, postal address, fax, and phonenumber to butterwo@ucar.edu


Story Source:

The above story is based on materials provided by National Center For Atmospheric Research (NCAR). Note: Materials may be edited for content and length.


Cite This Page:

National Center For Atmospheric Research (NCAR). "Increasing Carbon Dioxide Threatens Tropical Coral Reefs." ScienceDaily. ScienceDaily, 2 April 1999. <www.sciencedaily.com/releases/1999/04/990401190824.htm>.
National Center For Atmospheric Research (NCAR). (1999, April 2). Increasing Carbon Dioxide Threatens Tropical Coral Reefs. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/1999/04/990401190824.htm
National Center For Atmospheric Research (NCAR). "Increasing Carbon Dioxide Threatens Tropical Coral Reefs." ScienceDaily. www.sciencedaily.com/releases/1999/04/990401190824.htm (accessed October 22, 2014).

Share This



More Earth & Climate News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

Reuters - Light News Video Online (Oct. 22, 2014) — The pair of rare white northern rhinos bring hope for their species as only six remain in the world. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
Trick-or-Treating Banned Because of Polar Bears

Trick-or-Treating Banned Because of Polar Bears

Buzz60 (Oct. 21, 2014) — Mother Nature is pulling a trick on the kids of Arviat, Canada. As Mara Montalbano (@maramontalbano) tells us, the effects of global warming caused the town to ban trick-or-treating this Halloween. Video provided by Buzz60
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) — He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

Newsy (Oct. 20, 2014) — The United Nations says water is a human right, but should it be free? Detroit has cut off water to residents who can't pay, and the U.N. isn't happy. 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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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