By Michelle Samuels
A little more than a year ago, Karina Scavo was growing coral in a lab to decorate fish tanks. Then she came to Boston University for graduate studies in marine biology, and by last December she was in ten feet of Caribbean seawater, growing coral for a global effort to save the reefs. It was an experience she never dreamed she would have as a first-semester graduate student—but this was an undergraduate class.
Coral Reef Restoration and Resilience, which debuted last fall, is a month-long BU Marine Program (BUMP) course in the tiny Central American nation of Belize, where students take a whole ecosystem into their own hands. Next month, another group of students will be headed to the reef. John Finnerty, the director of BUMP, had the idea while teaching another Marine Semester course in Belize. There, he saw a rack of coral transplants, grown to rebuild the reef. “Rather than merely documenting the decline in marine habitats,” the associate professor says, “I thought there might be an opportunity for BUMP students to ‘fight back’.”
To teach the course, Finnerty turned to biology professor Les Kaufman, “our resident coral expert.” Corals are a strange and delicate form of life, colonies of tiny invertebrates building sprawling structures from the stony exoskeletons of each successive generation, fed by the photosynthesis of microscopic organisms or symbionts living inside them. Their ideal temperature is around 29º Celsius, but Kaufman says one degree hotter for more than five days causes “bleaching,” where the symbionts abandon the coral, and the coral starves. Climate change also means more violent and frequent storms, which bust up reefs, and higher acidity in ocean water, which dissolves the limestone coral uses to heal breaks. Bacteria from human waste can cause diseases in coral, and our overfishing removes species that graze competing seaweed and algae, and eat the coral’s predators.
Coral is up against a lot, but Kaufman says it should have us on its side. Reefs bring in millions of dollars in ecotourism, support the fish populations that feed coastal communities, and protect beaches from hurricanes. Kaufman says humans, now in the midst of a global mass extinction, are in a Noah-like situation: “Who are we going to take with us?” As with Noah the situation is a dark one, for we are ourselves the cause of the extinction wave, just as human mischief was the reason for the biblical flood. Ensuring the future company of all those different species isn’t just a matter of being able to have pretty zoos down the road, either. Human life is dependent upon biodiversity, the full panoply of living things doing what they do in the wild.
For a future that includes coral, we need to know more— the human stewardship that can help it to flourish. What is the biodiversity that helps reefs stand up to human environmental pressures, and how do we sustain this variation? That’s where Coral Reef Restoration and Resilience comes in.
The nine students in last fall’s class spent the first two weeks of the course at BU, learning to identify corals and the countless creatures that call the reefs home, so that they could take surveys of a range of coral-related factors. They also studied Belize, its history, government, and economy, to understand why that country—smaller than Massachusetts—has given its reef so much attention, and what dangers the reef still faces. That part of the class comes courtesy of Coupled Human and Natural Systems (CHANS), a program at BU led by Kaufman and stretching across computer science, ecology, economics, international relations, and even theology to find big-picture solutions to global environmental problems.
Finally, after two weeks in the classroom, the students dove in. With snorkels.
Turneffe Atoll is a marine reserve in Belize. In the comparatively hospitable waters of the atoll’s Calabash Caye, the class worked with the coral-rearing NGO Fragments of Hope to set up their rearing table. It’s a three-by-four-meter structure of rebar hammered into the sea bottom, supporting polypropylene ropes holding pieces of coral. Those pieces are harvested from healthy reefs, then grow, and grow, until they’re ready to be transplanted. “You can propagate coral like you can propagate plants,” Karina Scavo explains. “If I have an entire colony, and I take branches off, I can grow a whole new colony from that piece.”
Still, BU’s rearing table is too small to produce much coral. Instead, research is the focus. Massive coral nurseries, like Fragments of Hope’s and others, can produce tens of thousands of pieces of coral a year. But simply growing and planting coral is no guarantee that bleaching, pollution, and overfishing won’t just destroy it again. The goal of the class, says Kaufman, isn’t to build reef, but “to build the science to make it work.” The hope is that experiments on BU’s rearing table will help bigger operations grow more resilient coral.
There’s a lot we don’t yet know about coral. Case in point: the same species—we think—can form completely different shapes, from fingers to lettuce leaves to big round blobs. That’s important, because denser shapes stand up better against hurricanes, while branching, spreading forms may capture more growth-powering light. Certain strains of within any species might also stand a better chance against heat and disease. Finding out how much of an effect the shape makes is one goal. Another is understanding the genes that power coral’s ability to grow in more resilient ways, so restoration efforts can produce tougher reefs.
During her twelve-hour days in the water, Karina was working on one factor. “I looked to see if the phenotype, or the appearance of the coral, was different in different environments,” she says. This was a preliminary study, and genetic testing is needed to get the full picture. Still, her snorkeling survey found coral on the edge of the reef, where it’s exposed to more “wave action,” grows thicker branches, perhaps to resist breakage. It also branches more intricately, which may mean more branching means more strength. Karina hopes to continue her research from the class for her doctorate, building up information until it translates into building resilient reefs back down in Belize, and beyond.
Coral grows slowly, and the scientific process takes time. Meanwhile, the forces that are destroying the reefs are massive and pervasive. Despite Belize’s protection efforts, global climate change continues to kill coral. “Ultimately,” Kaufman says, “we need to solve the climate problem, or there won’t be any corral reefs.”
Karina says things may seem daunting and incredibly dire on a global scale, but she derives hope from Kaufman’s approach. It, like this class, is site-specific, working with local human populations and looking for all the factors—tides, fish, temperature—to keep individual coral populations healthy. “Once we do that,” she says, “we can grow coral in an environment that we know it’ll do well in.” One site at a time, she hopes the reefs can be saved. In that long and difficult process, there will be nine more BU students this December, to don their snorkels and take the hands-on approach.