"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
|Contact: Tara Hicks|
University of Hawaii at Manoa