The coral doctor: Foster Scholar Michael Fox gives corals the best chance he can

By Yaamini Venkataraman

March 2018

When faced with a devastating flu season, we humans look to public health specialists. When exposed to changes in their environment, corals can get sick too. When corals are not healthy at Hawaiian Islands Humpback National Marine Sanctuary and Pacific Remote Islands National Marine Monument, Michael Fox is on the case.

As a Dr. Nancy Foster Scholar, Fox is a public health planner for coral reefs. Like his human-focused counterparts, he wants to know when corals are most susceptible to stress and what makes some coral populations more resilient than others. For his Ph.D. at Scripps Institution of Oceanography at the University of California, San Diego, Fox wants to know if pollution or other water quality measurements can explain these differences.

Don’t be fooled by a coral’s hard exterior — they are actually living, breathing communities. Embedded within individual coral polyps are single-celled algae called zooxanthellae. The zooxanthellae photosynthesize and provide the polyp with food in exchange for a home. These partnerships are sensitive to even the smallest change in water quality: if corals are stressed, they eject the zooxanthellae. This turns once colorful and vibrant reefs into fields of white coral skeletons, a process known as coral bleaching.

But not all coral reefs bleach when faced with similar stressors. When coral reefs are the backyard of large cities, pollution can be one of the more common stressors the reefs face. To figure out if polluted reefs bleach more often, Fox works with researchers at the University of Hawai‘i, Manoa, University of Rhode Island, and the NOAA Coral Reef Ecosystem Program. Together, these researchers work to determine how nutrient pollution (think fertilizer) affects corals and their relationship with their symbiotic algae.

When faced with stressors like pollution or abnormally warm waters, the tight relationship between coral and zooxanthellae can break down. By linking pollution levels with changes in this partnership, Fox hopes to figure out if more polluted reefs are susceptible to bleaching.

“We’re trying to make a land-sea connection to how people manage pollution onshore, and how they impact the reefs,” Fox says.

Fox’s interest in how corals respond to their environment doesn’t stop with the Hawaiian Islands. Returning to Palmyra Atoll in the remote equatorial North Pacific after a bleaching event last year, Fox found that less than 15 percent of corals had died. In a related study, Fox compiled a global dataset for 15 different coral species and he found evidence that corals tend to eat more in areas with greater food availability. Fox believes that food availability is an important factor that could help sick corals recover from bleaching events like the one on Palmyra.

Atolls consist of ring-shaped coral reefs surrounding a lagoon. At Palmyra, the water from the lagoon drains onto the reefs, bringing with it zooplankton — coral food. If there is more food available in certain areas of Palmyra, Fox says, the corals that live there might “come back more quickly and strongly.” His goal is to first measure the amount of zooplankton consumed by corals, and then figure out areas of the atoll that receive more nutrient-rich lagoon water recover faster.

So corals react to pollution, but can recover with enough food — now what? For Fox, the next step is the most important one: applying his work to management. He is working on creating resilience metrics, or easily-identified indicators on the reef that resource managers can use to evaluate the reef’s health. He favors using readily-available information, like remote sensing of the ocean’s color.

“My work has made a connection between data that anyone can use for free, and physiology of corals themselves. Just by looking at satellite data, managers can start thinking about which areas might recover more effectively from the next bleaching episode,” Fox says. “We’re trying to give managers tools to make the decision that best benefits them and their objectives.”

Because of NOAA’s Dr. Nancy Foster Scholarship Program, Fox has been able to translate his science to policy. He credits the “middleman” nature of national marine sanctuaries as providing opportunities to translate his field and lab work into useful information for resource managers and the general public.

“Going into the field is one of the most exciting parts of the job, and [it] inspires you to do all of the hard work and try to apply that to informing the public about the state of different ecosystems, be it coral reefs or sea ice in the Arctic,” Fox says. “[You can] use that information to inspire people to change their actions and provide decision makers new strategies to manage resources more effectively.”

Even though Fox will finish his dissertation this spring and jumpstart the rest of his journey, it’s clear that he’s already fulfilled dreams and promises he’s made in the past. According to his parents, Fox has wanted to be a marine biologist since he was two years old. At the beginning of his coral science career, Fox promised as an undergraduate to give coral reefs “as much of a chance going forward” as he can. During his time as a Dr. Nancy Foster Scholar, he’s conducted crucial research, collaborated with leading coral scientists, and assisted resource managers. Neither undergraduate nor toddler Fox could have ever predicted this.

Yaamini Venkataraman is a volunteer social media intern for NOAA’s Office of National Marine Sanctuaries and a graduate student at the University of Washington.