Earth sciences professor puts Ohio State on the map of coral research

Andrea Grottoli, professor of earth sciences at Ohio State, has studied the effects of climate change coral reefs. Credit: Courtesy of Andrea Grottoli

If a colorful marine organism is the last thing you’d expect to hear about in Columbus, that’s only because you haven’t spoken to Andrea Grottoli, professor of earth sciences at Ohio State.

As director of the Coral Bleaching Research Coordination Network, president of the International Coral Reef Society and author of a paper on how coral’s microbiome affects its resilience to climate change, Grottoli is putting Ohio State on the global map of coral research.

“Reefs provide animal protein — fish — as the single largest source of animal protein for huge numbers of people in developing countries,” Grottoli said. “So, just from a human, economic and coastal preservation perspective, coral is hugely important.

Coral reefs host between 25 and 30 percent of all marine species, yet occupy just 0.2 percent of the surface area of the ocean, Grottoli said.

She also warns that coral bleaching, a reaction coral undergoes when faced with high levels of environmental stress, is becoming more common as ocean temperatures rise and waters acidify, threatening the world’s oceans.

One way Grottoli is trying to help us understand this issue is through the Coral Bleaching Research Network, which she directs. The network was recently funded by the National Science Foundation and will hold three workshops in the next three years, two of which will be at Ohio State.

“The goal is to make recommendations for experimental design, sample archiving and data synthesis, so that we can move the rate of scientific discovery about coral bleaching forward faster, more efficiently, and for less money,” Grottoli said.

Grottoli was also recently appointed as president of the International Coral Reef Society, an organization which she called the “voice of coral reefs.” One of the main goals of the organization is to interface with policy makers, and have their voice heard.

“It is very urgent,” Grottoli said about the future of coral reefs. “Any conservation efforts we put into place now are short term solutions to preserve reef ecosystem function long enough, so that we get to a point where climate change is starting to be mitigated.”

Questions about the resilience of coral reefs are what Grottoli’s 2018 study, published in the journal PLOS One, sought to answer by looking at coral microbiomes.

Michael Wilkins, adjunct assistant professor in the School of Earth Sciences and co-author of the study, said microbiomes are important because of the many interactions they have with the environment.

“Microbiomes are basically collections of microorganisms that are interacting with each other, interacting with their hosts — as in the case of corals — or interacting with the environment, like driving biogeochemical cycles,” Wilkins said. “So, they’re really important.”

The study compared a coral species that has a sensitive microbiome to one with a more robust microbial community, to see if they fared differently under conditions of increased water temperature and elevated water acidity — two of the main consequences of climate change.

It also found that the species with a sensitive microbial community experienced much higher dramatic physiological declines under climate change conditions, while coral with the more robust microbiome fared much better.

Most of coral’s microbiome lies in a mucus layer that surrounds the animal. While this layer acts as a protective barrier for the coral, the function of the microbiome itself remains relatively unknown.

Wilkins said that by amplifying certain marker genes from these samples, researchers are able to identify which specific microorganisms are present, an important step in understanding the makeup of a microbiome and any implications for its host.

Research is ongoing to figure out the precise role of coral’s microbiome in its physiology, and whether a causal relationship exists between the resiliency of coral’s microbiome and coral’s ability to survive the harsh conditions of global warming.

According to the paper, the future makeup of reefs might be predicted by which corals have more resilient microbiomes, since these species may be more likely to survive changing ocean conditions.

“They are the rainforest of the ocean,” Grottoli said.

Grottoli said it’s up to us if they survive.