Researchers say viral disease – particularly herpes – might have a role in the worldwide decline of coral.
It appears that corals harbor many different viruses – particularly herpes. Corals also are home to the adenoviruses and other viral families that, in humans, can cause colds and gastrointestinal disease. The findings appeared a research review published in the Journal of Experimental Marine Biology and Ecology, according to an Oregon State University press release.
The review authors point out that world coral declines are reaching crisis proportions. Rebecca Vega-Thurber is an assistant professor of microbiology at Oregon State University. She said:
Coral abundance in the Caribbean Sea has gone down about 80 percent in the past 30-40 years, and about one-third of the corals around the world are threatened with extinction.
Vega-Thurber said that researchers have identified 22 kinds of emerging diseases that affect corals, but still don’t know the pathogens that cause most of them. She said:
Most researchers have looked only at bacteria. But we suspect viruses may play a role in this as well.
An Oregon Statue University research program is studying viral “metagenomics” in corals – that is, analyzing multiple genomes at the same time – to help identify the underlying causes of coral decline. Vega-Thurber said that it may also shed light on the broader range of viruses that affect not only corals but many other animals, including humans.
One of the surprises from recent research was the predominance in corals of herpes viruses – similar but not identical to the herpes virus that can infect humans. Herpes viruses appear to constitute a majority of the viruses found in corals, and one experiment showed that herpes-like viral sequences were produced in coral tissues after acute episodes of stress.
It’s not yet certain, the researchers said, whether the viruses being found on corals are actually causing diseases. Vega-Thurber said:
Just because you harbor a virus doesn’t mean you are getting sick from it. This is part of what we have to pin down with further research.
Some of the possible causes of coral decline that have been identified so far include global warming that causes coral bleaching, loss of symbiotic algae that help nourish corals, pollution such as sewage runoff, and human-coral interactions.
Bottom line: A research review published in the Journal of Experimental Marine Biology and Ecology suggests that viral disease – particularly herpes – might have a role in the worldwide decline of coral, according to a press release from Oregon State University.