Inside the Coral Crisis

A Coral Imperative: A look at how marine scientists at UM are leading the race to restore endangered reefs—and why they say failure is not an option.

(August 26, 2013) — The marks on the kitchen-sink-size basin of seawater read 31°. 900 ppm. The first number is the water’s Celsius temperature, the second its acidity level. Together the measures simulate extreme conditions predicted for marine life off Florida’s coast and throughout the tropics by the turn of the next century.

From his open-air, sun-baked space on Virginia Key, Christopher Langdon keeps a close watch on how the corals in this and a dozen or so other basins scribbled with equally cryptic calculations are faring.

Some of them, it seems, are not long for this world.

“Lots of coral biologists are making predictions about what’s going to happen in 100 years,” says Langdon, a professor at the Rosenstiel School of Marine and Atmospheric Science and co-founder of the South Florida Corals and Climate Change Laboratory. “They’re basing that on experiments where only one variable has been manipulated—temperature—and more recently pH. But almost none have looked at what happens when both conditions change. I don’t have the answers yet, but that’s the direction my lab is taking. Maybe some coral species will prove to be more resistant than others, but the ones that I’ve looked at such as Acropora cervicorni and Porites porites [staghorn and finger coral] are really taking it on the chin.”

Langdon is just one of the scientists at the Rosenstiel School whose coral research and restoration studies are deepening our understanding of how numerous factors—many rooted in human activity, such as overfishing, burning of fossil fuels, and continued deforestation—affect the health of coral reefs in Florida and around the world.

Their work will be further supported and enhanced with the completion later this year of the new Alfred C. Glassell, Jr. Surge-Structure-Atmosphere Interaction Building and Laboratory and adjoining Marine Life Sciences Building, funded by a $15 million grant from the National Institute for Standards and Technology and $5 million gift from Glassell’s family in his memory. The marine facility will give Langdon and his colleagues significantly more aquaria space and unite their labs under one roof for the first time.

“There are very few major universities in the world that are as close to coral reefs as we are,” says Langdon. “We’re really ideally placed for this work, and this building should give us one of the best facilities in the world for coral studies.”

The school’s scholarship of reef systems, often called the rainforests of the seas, dates back to the days of its founder, F. G. Walton Smith, who wrote a popular guide to identifying Atlantic corals. But during the past decade, mainstream attention to the field has skyrocketed.

Still, there remains a lack of widespread awareness of just how important coral reefs are to us. According to Langdon, Florida’s reefs represent nearly $6 billion of the state’s annual economy. That’s because they serve as the breeding ground for much of the marine life that supports Florida’s fishing industry. They also are responsible for our clear blue waters, which lure tourists the world over. Perhaps most critical, reefs such as the Great Florida Reef, which runs the length of the Florida Keys, protect us land dwellers—and the land itself—from the torrential impact of hurricanes and other storms.

“It’s a living sea wall, and if it was gone, all that land would pretty quickly wash away,” says Langdon. “It’s completely self-sustaining and repairs itself. You can imagine what it would cost the Army Corps of Engineers to build a sea wall from here to Key West. The reef is doing that by itself, and all we have to do is take some precautions and it might be here forever.”

Langdon’s colleague Andrew C. Baker, Ph.D. ’99, associate professor of marine biology and fisheries, is making valuable discoveries about coral’s symbiotic relationship with a one-celled creature key to its survival.

Employing advanced genetic testing, Baker and the students in his lab examine the DNA of coral polyps and their plant-based symbiotic feeding partners in the genus zooxanthellae in hopes of finding a scientific solution to the killer phenomenon of coral bleaching.

Changes in water conditions caused by any number of manmade or naturally occurring events, from farm runoff to El Niño storm systems, can disrupt the delicate housing arrangements between coral and their colorful algae tenants. Periods of warming or increased acidification can serve as a sort of eviction notice for the zooxanthellae, who are expelled en masse from their calcified landlord. The term “coral bleaching” refers to the suddenly pale look of the reef at the site of the algae exodus.

Baker’s lab wants to know what may help certain corals better handle such situations of extreme duress.

“We now think that under certain circumstances, corals can switch or shuffle different types of algae and, in so doing, respond to changes in their environment,” says Baker. “It’s kind of like adapting but in very fast ecological time as opposed to long-term Darwinian natural selection.”

In these dire straits, time is of the essence. If the “bleached” coral doesn’t regain access to nutrients in time, it starves to death. Ph.D. candidate Erica Towle was awarded a research grant by the Mohamed bin Zayed Conservation Fund to hunt for signs of resilience in the DNA of Acropora cervicornis, staghorn coral, before it’s too late. She says more than 80 percent of the world’s staghorn population has disappeared in just 30 years due to disease, climate change, and human-related factors; it is now on the International Union for Conservation of Nature’s Red List of Threatened Species. “The staghorn coral used to be one of the dominant reef builders in the Florida Reef Tract,” she says.

Another genetic study Baker conducted with Ph.D. students appeared in the Proceedings of the Royal Society. It determined that coral species tend to have “preferences in their algal partners” but also appear to be able to take new algal partners “in response to environmental changes,” says doctoral candidate Rachel Silverstein. According to another study published by lead author Ross Cunning, also a Ph.D. candidate in Baker’s lab, the more symbiotic algae a coral reef is inhabited by, the more vulnerable the reef is to the impact of bleaching.

Together these key insights may prove immensely beneficial to coral restoration efforts. Ultimately they may enable Baker’s lab to produce a genetically formulated “inoculation” of zooxanthellae that would make coral more resilient to future change. Baker points out that this solution would be impractical on a massive, global scale but could be enormously helpful in nursing degraded reefs or maintaining coral nurseries.

Associate professor Diego Lirman, Ph.D. ’97, who runs the Benthic Ecology Lab at Rosenstiel, has been perfecting the science behind coral restoration methods for years. His nursery is located in Biscayne National Park just 45 minutes from campus by boat. So far it has been tremendously successful, growing within two years from 6 meters of collected wild coral to 260 meters of coral available for transportation to ailing reefs.

But promising as these results seem—and Lirman is quick to credit the work of coral nursery pioneer and Rosenstiel School partner Ken Nedimyer, president of the Coral Restoration Foundation—coral nurseries won’t outpace the damage being wrought on our reefs, he says. “Can the coral reforestation we’re doing solve the problem?” asks Lirman. “No. But what we’re doing is re-establishing populations in places where there are no longer viable reproductive corals. We’re bridging the gap. Hopefully they will become sexually reproductive populations that eventually contribute to restoration of the species.”

Baker and Langdon echo Lirman’s sense of urgency and perspective. However crucial and groundbreaking their work is, they recognize it as one step toward the collective awareness and effort that will be needed to save our reef systems.

To that end, a delegation of more than 25 Rosenstiel School faculty and students attended the Olympics of coral research, the International Coral Reef Symposium, last July in Cairns, Australia, conferring with investigators from around the globe on the latest, most promising advances and issues in coral research.

“The idea is that we have to reduce the damage of all the things we can control,” says Langdon. “It’s like first aid—it’s not going to solve the problem, but it’s going to buy you time to get other help. It’s what we can do today.”

In that spirit of informed caution and cautious optimism, their work continues.

“I could be pessimistic for half a dozen reasons,” says Baker. “Having said that, we haven’t documented a single case of a coral species going extinct yet, so currently all the pieces of our jigsaw puzzle are still there. I’m fairly confident that within my own lifetime we’ll come up with some sort of solution. The question is, how much of the natural world will we have left to save when the solution comes?”

- By Jason Fitzroy Jeffers

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