Outbreak

Even healthy corals have viruses

Role of viruses could reveal more about reef decline

Microbiologist Rebecca Vega Thurber and her team research advanced genomic approaches for identifying infections of corals. Their recent research on the role marine viruses play in healthy corals and the impact they have on reef decline is one of the first studies to show viral association with a severe disease epidemic.

In the largest and longest experiment of its kind, Vega-Thurber and her collaborators conducted a controlled study of the impact of pollution upon corals at a study site in Florida Keys from 2009-2012. The experiment, whose findings were published in “Global Change Biology,” shows that while pollution from sewage and other sources caused high levels of coral disease and discoloration, corals were able to swiftly recover once the injection of pollutants was stopped.

Corals are important ecosystem engineers, providing habitat and nutrient recycling to tropical reefs. However, coral species' richness and abundance are declining worldwide, largely due to impacts from global industrialization and human population growth. In the Caribbean, coral cover has shrunk from 60% to 5%, according to Vega Thurber.

Coral disease is a major cause of the decline of tropical reefs, making research into the causes of and remedies to these diseases extremely important.

Vega Thurber and her team have been studying viruses inside the corals, even healthy corals. They collect coral samples during diving expeditions and analyze the DNA to learn more about the role of viruses in corals.

With funding from the National Science Foundation (NSF), Vega Thurber and her research team have also studied the deadly coral disease called “white plague” that has erupted among tropical corals. White plague is characterized by rapid tissue loss, which exposes the white skeleton of the coral. This disease has been implicated in reef decline worldwide, although their etiological cause is unknown.

Previous studies focused on bacterial pathogens as the primary cause of coral diseases. The notion that almost all corals have viruses was a revelation to researchers.

Vega Thurber’s research on the role of viruses in coral reef ecosystems has received extensive coverage and recognition in popular media. A number of studies on coral disease by members of the Vega Thurber lab have made their way into popular media, including Stephen Colbert’s Colbert Report, CBS This Morning, and Phys.Org.

Vega Thurber runs a highly dynamic, hands-on laboratory where her students gain ample research experience, essential skill sets and other valuable opportunities to pursue independent research. Her students have undertaken ambitious projects to further understand and protect one of the world’s most fragile and essential ecosystems.

Student research on corals

Nitzan Soffer’s doctoral research in microbiology revealed viruses to be at the root cause of coral epidemic of “white plague.” His research was featured on NBC News.

Ryan McMinds, a doctoral student in microbiology, spent last summer on Australia’s Lizard Island studying healthy microbes in coral reefs. His research was funded by the East Asia and Pacific Summer Institutes program.