Featured Research

from universities, journals, and other organizations

Predicting Coral Health By Identifying Nearby Microscopic Algae

Date:
July 23, 2008
Source:
University of Hawaii at Manoa
Summary:
A new indicator of coral health has been discovered in a community of microscopic single-celled algae called dinoflagellates. The study reveals that a particular type of these algae renders corals more susceptible to disease.

A diseased coral.
Credit: Michael Stat, HIMB/SOEST

A new indicator of coral health has been discovered in a community of microscopic single-celled algae called dinoflagellates. The study reveals that a particular type of these algae renders corals more susceptible to disease.

"Corals are fascinating organisms whose survival is dependent on dinoflagellates that live inside the coral's tissue," says lead author Michael Stat, an assistant researcher at the Hawaii Institute for Marine Biology (HIMB) at the University of Hawaii at Manoa. "The relationship between these dinoflagellates and corals has long been considered mutually beneficial, with the dinoflagellates supplying the coral with food via photosynthesis in return for recycled nutrients and shelter. Over the last 20 years it has been made clear that there are many different types of dinoflagellates in corals and that the unions or symbiosis between a given coral and their dinoflagellates can be very specific."

It had previously been considered that all dinoflagellates found in coral are equally beneficial to their coral host, but in this study Stat, along with HIMB researchers Ruth Gates and Emily Morris, present evidence that a particular type of dinoflagellate can be found in corals that are diseased or show evidence of having had a disease.

"We show that this same symbiont, called "clade A", does not produce as much food that can be used by the coral as other types of coral dinoflagellates," says Stat. "We suggest that because these coral are not receiving enough food they become more prone to disease."

The researchers sampled corals that appeared healthy and corals that appeared diseased from French Frigate Shoals in the Papahanaumokuakea Marine National Monument in the Northwestern Hawaiian Islands (NWHI). By using genetic analyses, they were able to identify the type of dinoflagellate that was present in each of these corals. They found that the healthy coral contained one type of dinoflagellate and the diseased coral contained a different type of symbiont.

"We have discovered that a group of diseased corals in the NWHI associate with a type of endosymbiotic algae that has never been found in Hawaiian corals before," says co-author Ruth Gates, an Associate Researcher at HIMB. "Our analyses suggest that these endosymbiotic algae are not providing the coral with nutrition and that the corals may be starving, making them more susceptible to disease."

To mimic the inside of coral tissue, they performed lab-controlled experiments looking at the amount of carbon produced and released by different coral dinoflagellates in an artificial environment. They found that the dinoflagellate found in healthy coral produced large amounts of carbon that it released into the outside environment, making it available to a coral as a source of food. In contrast, the dinoflagellate found in diseased coral produced a very small amount of carbon and did not release any to the outside environment to make available to a coral host as a source of food.

"Just as we have tests for human diseases such as cancer and tuberculosis, we now have the ability to screen corals for disease susceptibility," says Gates. "This discovery is a key finding that will contribute to the conservation and protection of ecologically important corals in Hawaii and elsewhere."

"This work shows for the first time that different types of coral dinoflagellates are not equally beneficial, and that there is a link between the type of dinoflagellate and coral disease," says Stat. "We also suggest that some dinoflagellates living inside coral may be acting more as a parasite than a mutualistic symbiont. The next stage in our research is to further understand the range of interactions between coral and dinoflagellates and to determine whether some types are directly harming the coral and acting as parasites."

This research was funded by the National Marine Sanctuary Program, the Hawaii Institute of Marine Biology Reserve Partnership and the National Science Foundation.


Story Source:

The above story is based on materials provided by University of Hawaii at Manoa. Note: Materials may be edited for content and length.


Journal Reference:

  1. Stat et al. Functional diversity in coral-dinoflagellate symbiosis. Proceedings of the National Academy of Sciences, 2008; 105 (27): 9256 DOI: 10.1073/pnas.0801328105

Cite This Page:

University of Hawaii at Manoa. "Predicting Coral Health By Identifying Nearby Microscopic Algae." ScienceDaily. ScienceDaily, 23 July 2008. <www.sciencedaily.com/releases/2008/07/080718085114.htm>.
University of Hawaii at Manoa. (2008, July 23). Predicting Coral Health By Identifying Nearby Microscopic Algae. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2008/07/080718085114.htm
University of Hawaii at Manoa. "Predicting Coral Health By Identifying Nearby Microscopic Algae." ScienceDaily. www.sciencedaily.com/releases/2008/07/080718085114.htm (accessed August 22, 2014).

Share This




More Earth & Climate News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Airlines on Iceland Volcano Alert

Airlines on Iceland Volcano Alert

Reuters - Business Video Online (Aug. 22, 2014) Iceland evacuates an area north of the country's Bardarbunga volcano, as the country's civil protection agency says it cannot rule out an eruption. Authorities have already warned airlines. As Joel Flynn reports, ash from the eruption of the Eyjafjallajokull volcano in 2010 shut down much of Europe's airspace for six days. Video provided by Reuters
Powered by NewsLook.com
Endangered Red Wolves Face Uncertain Future

Endangered Red Wolves Face Uncertain Future

AP (Aug. 22, 2014) A federal judge temporarily banned coyote hunting to save endangered red wolves, but local hunters say that the wolf preservation program does more harm than good. Meanwhile federal officials are reviewing its wolf program in North Carolina. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Coal Gas Boom in China Holds Climate Risks

Coal Gas Boom in China Holds Climate Risks

AP (Aug. 22, 2014) China's energy revolution could do more harm than good for the environment, despite the country's commitment to reducing pollution and curbing its carbon emissions. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Microbrewery Chooses Special Can for Its Beer

Microbrewery Chooses Special Can for Its Beer

AP (Aug. 22, 2014) Aluminum giant, Novelis, has partnered with Red Hare Brewing Company to introduce the first certified high-content recycled beverage can. (Aug. 22) Video provided by AP
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