Bracing for Impact

MEXICO’S CARIBBEAN COAST IS HOME TO more than 300 hotels with some 100,000 rooms. Every year approximately 12 million visitors spend $9 billion here, and a significant portion of that spending is directly related to the Mesomerican Reef, in the form of activities like diving, snorkeling and sportfishing tours.

But Mexico’s reefs are suffering. A 2018 report found 50 percent of the country’s reefs in poor or critical condition. Reefs around the globe offer a similarly grim picture: Roughly half of the world’s coral reefs have died in the past 30 years, and scientists predict that most of the rest will be gone by 2100 unless people find a way to reduce pollution, overfishing and climate change.

That will be a catastrophic loss. Even though they fill less than 1 percent of the ocean floor, coral reefs are home to a quarter of the world’s fish species. They provide food and income for 500 million coastal inhabitants. And they protect shorelines from flooding and beach erosion by absorbing up to 97 percent of the energy of incoming waves.

While humanity confronts the long-term threats facing coral reefs, in the short term hurricanes pose a big problem. A damaged reef can’t provide an eff ective shield against waves and is itself more vulnerable to powerful storms. In the Mexican Caribbean, hurricanes are one of the leading causes of reef damage, through the direct pounding action of waves and from debris washed out from the shore. Limbs of elkhorn and staghorn corals snap off like branches in a tornado; brain corals the size of beach balls are knocked over or turned upside down, their outer, living layers shattered. Buried in sediment, their symbiotic algae unable to photosynthesize, the coral fragments will die.

Unless someone fixes them, that is.

HOTEL OWNERS ON MEXICO’S CARIBBEAN COAST insure their facilities against storm damage, says Miguel Diego, who manages the Zoetry Paraiso Resort near Puerto Morelos. But the beaches outside their facilities have been another story. Storms often sweep away beach sand, forcing property owners to truck in replacement material. It’s expensive to fix, and most owners are deeply concerned about beach erosion, he says. When TNC approached the Cancun and Puerto Morelos Hotel Association about finding a way to repair coral reefs, it embraced the idea as a way to protect precious sand.

“Hotel owners are looking to protect their investment, but we do see the horizon,” Diego says. “We need to be responsible and be good stewards of the resources we have.”

The concept of repairing barrier reefs like the one off Puerto Morelos makes perfect sense, says Fernando Secaira, who leads TNC’s climate and risk resilience initiative in Mexico. “They provide an economically valuable service, they’re at risk and they can be repaired with enough money,” he says.

In fact, repair is one of the most cost-effective options for protecting beaches. Secaira estimates that using the first-response diving team to quickly repair the hardest-hit portions of the national park’s 17 miles of reef after a hurricane will cost between $50,000 and $150,000, compared with the roughly $1 million hotels pay to install half a mile of sea wall or other artificial protection. “From an economic point of view, it makes so much sense,” Secaira says.

And Secaira well knows that time is running out for reefs if such repairs don't take place. Hurricanes are simply a fact of life on the Yucatan Peninsula—and each big storm breaks down part of the remaining 20 percent of living reef. With every loss, the remaining reefs become less and less able to regenerate themselves.

Secaira spent several years brainstorming with state government representatives and coral reef experts about how to sustain the reefs near Puerto Morelos. Those conversations culminated in March 2018 when the state government of Quintana Roo announced it would create a new kind of environmental trust. As envisioned, the Coastal Zone Management Trust will be able to pay for beach dune and reef maintenance, including reef rescue dive teams to jump into action after a major hurricane hits. It will be funded in part by the beach lease tax paid by hotel and resort owners to the federal government.

PRIOR TO THEIR FINAL EXAM, the prospective members of the Guardians of the Reef spent one day in the classroom and three days in the water honing their skills. They studied coral ecology and learned how to identify priority areas for repair after a storm.

“You don’t have too much time,” says instructor Calina Zepeda, a TNC restoration specialist who wrote the protocol for the course. “You have to work as fast as you can—damaged parts of the reef can die in 45 days.”

The divers also learned skills such as using pneumatic drills underwater and inserting metal rods to keep larger pieces of reattached coral in place, set like broken bones in people. They practiced with cement and marine epoxy on pieces of dead coral, and learned how to inflate nylon lift bags to move large pieces of coral and storm debris. Even though the participants were all experienced divers or snorkelers, “90 percent of them had never done this work before,” Zepeda says.

Now, 15 feet deep, the divers split up to demonstrate their repair skills on two broken stands of elkhorn coral. Blue tangs, Moorish idols and other fish flit between purple sea fans and coral outcroppings that occasionally break the surface. Guerrero picks up an arm-sized branch of elkhorn coral and finds a nearby spot on the reef where it might fit.

A diver signals one of the three snorkelers circling above to swim down and hand her a large white zip tie. She scrubs the attachment point with a wire brush until it’s clean and white. Then she holds the broken piece in place while Guerrero tries to reattach it with a zip tie.

A task that would be simple on land becomes something else entirely underwater. The gentle undulations of the waves make it difficult to stay in one position. The divers have to be careful not to break any living coral in the process, and they can communicate only through hand signals. It’s like grafting a branch onto a tree after three stiff drinks, with a partner who speaks a different language.

Other divers tie their pieces on with tarred string. Then they apply cement to the junction by hand. Every time someone opens the cement bucket, a gray cloud momentarily envelops the workspace. The gritty paste on the repair site will harden in three days, and in a month—if the reattached piece lives—the coral will grow over the material.

Although the national park protects one of the healthiest reef systems in the Mexican Caribbean, with the largest stand of elkhorn coral in the region, “health” is relative, says Zepeda. “The coral in Puerto Morelos is not in the best shape,” she says. Poorly regulated development has caused erosion and pollution. And storms have taken their toll.

Yet Puerto Morelos has so far avoided much of the explosive growth and pollution seen in places like Cancun and Playa del Carmen. Plus, the small city, population 13,000, hosts a campus of the National Autonomous University of Mexico (UNAM) and a research center of the National Fisheries and Aquaculture Institute (CRIAP), making it a good place to launch an experiment in saving reefs. The Conservancy has tapped many experts with different viewpoints to come together around this effort, says TNC’s Zepeda. “We connect groups that sometimes don’t even speak,” she says. “It’s better to work as a team when resources are limited.”

Of particular interest have been experiments conducted by CRIAP’s research center, which is testing a relatively new coral-propagation method called microfragmentation, first developed at the Mote Marine Lab in Florida. Compared with the finger-sized pieces of hard coral that the lab also grows in land-based tanks, microfragments consist of just a few individual polyps, the tiny animals that make up corals. These soft bits of coral grow very quickly on centimeter-sized bits of epoxy in laboratory tanks. The accelerated growth allows biologists to quickly produce plates of coral tissue that can then be attached to artificial structures or even the skeletons of dead corals out in the wild. A microfragment colony should reach sexual maturity faster than corals would in the natural environment, says lead researcher Claudia Padilla Souza. Her team aims to produce about 32,000 microfragments in 2018, she says, and will soon plant its first microfragment colonies in the sea.