VEGA BAJA, PUERTO RICO — Ricardo Laureano suspected there was something special about the elkhorn corals of El Eco Reef in northern Puerto Rico. In his 16 years of protecting and monitoring their growth, the self-described coral reef has seen few cases of bleaching, a problem that is increasingly ravaging corals over time. global scale. Scientific discoveries proved Laureano right. The reef it protects is essential to combating the effects of climate change on the archipelago.
A 2024 study in Marine and Environmental Archeology suggests that the El Eco Reef has survived since pre-Hispanic times, potentially due to genetic variation that makes the coral resistant to bleaching. Bleaching occurs when rising water temperatures force corals to expel photosynthesizing algae, leaving reefs ghostly white. Local scientists now believe El Eco’s corals could help repopulate bleached reefs and mitigate other climate-related disasters.
“It’s Puerto Rico’s last jewel in coral conservation,” says Edwin Hernández, senior scientist at the Marine Environment Society, an organization dedicated to reef restoration in Puerto Rico.
At first glance, elkhorn coral looks like an underwater hand reaching toward the sky. One of the most important corals in the Caribbean, it provides habitat for many species, and its rapid growth and location on the reef allows it to withstand the impact of waves. The species has been listed as “threatened” under the U.S. Endangered Species Act since 2006, and as global temperatures rise, its populations are more threatened than in the past. It resists bleaching better than other species and shows signs of branching and resistance to higher temperatures, but cannot completely outcompete it.
In 2023, the Caribbean recorded its worst mortality from coral bleaching since 1987. By October, mass bleaching affected more than 95% of Puerto Rico’s corals, in what technical reports from the Marine Environment Society described as a “unprecedented” marine heat event.
Hernández says all elk colonies have died in Cabo Rojo, on the southwest coast of the archipelago. Only sporadic populations survived in other regions. But in Vega Baja, where El Eco Reef is located, coral mortality was only 1.7 percent.
Climatic anomaly
Mariela Declet, a marine biologist and environmental archaeologist, looks to history to explain the resilience of El Eco’s corals. Through zooarchaeological analyses, which study the remains of animal bones, Declet discovered that centuries ago, this coral had survived temperatures similar to those of today.
Between 800 and 1300 AD, the Northern Hemisphere experienced changes in temperature and a high incidence of hurricanes. Evidence points to massive coral bleaching between 900 and 1000, which affected the northern and southern coasts of Puerto Rico. But, as Declet describes in his doctoral thesis at the University of California, the El Eco corals managed to adapt and survive.
Between 2008 and 2019, around 14% of the world’s reefs disappeared due to bleaching. If no protective measures are taken, scientists predict that 99% of these ecosystems could disappear by the end of the century. This would result in loss of habitat for 25% of known marine species, the collapse of the fishing industry and greater exposure of coastlines to ocean forces.
Worldwide, nearly 200 million people rely on coral reefs for protection from storm surges and waves, as these ecosystems can reduce wave energy by 97% and decrease wave heights by 84%.
Every year, in the United States alone, coral reefs protect about 18,000 people from flooding and prevent about $825 million in damage, according to a 2019 United States Geological Survey study. he main island of Puerto Rico would face the worst flooding in the United States without coral reefs.
For Declet, the resilience of El Eco’s elkhorn corals offers “a sense of hope” for the conservation and reproduction of the species.
In 2023, Vegabajeños Impulsando Desarrollo Ambiental Sustentable (VIDAS), a volunteer organization led by Laureano, transplanted some of the El Eco corals to El Escambrón beach in San Juan. Hernández, who monitored the area, says the specimens began to branch and show resistance to high temperatures.
This exercise could be replicated in other neighborhoods of the Puerto Rican capital to prevent flooding. In 2023, the Federal Emergency Management Agency approved $3 million under the Hazard Mitigation Grant Program for the first phase of reef restoration off San Juan. Nilda Jiménez, endangered species program coordinator at Puerto Rico’s Department of Natural and Environmental Resources, says the department is considering El Eco corals for the project.
But scientists recognize that with ocean temperatures rapidly increasing, success is not guaranteed. “At this rate,” said Declet, “we don’t know what will survive and what won’t. »
In October, El Eco experienced bleaching due to high water temperatures, Hernández says. According to his preliminary estimates, around 5% of the coral population has died.
Protect the reefs
Although El Eco corals are resilient, that doesn’t mean they always will be, Jiménez cautions. She believes it is necessary to continue identifying resilient coral colonies and focus on reef protection.
A 2022 study by Rutgers University, the Coral Reef Alliance and other institutions concludes that preventing water pollution, avoiding overfishing and eliminating other risk factors will help resilient strains thrive and survive. repopulate other reefs.
In August of this year, the government of Puerto Rico signed a law declaring the El Eco Reef part of the Vega Baja and Manatí Underwater Gardens Nature Reserve. The measure guarantees $1 million in annual funding to preserve elkhorn coral and other species. VIDAS’ Laureano also aspires to promote studies of genetic variability and monitor water quality and temperature, among other initiatives aimed at preventing reef deterioration.
José Antonio Vargas, the senator who introduced the law to protect the reef, told the Global Press Journal that the designation of the reserve will allow “a special level of care” for the elkhorn coral.
Meanwhile, Laureano and other Vega Baja volunteers continue to work to protect the reef. Now that he knows why the corals he has cared for over the years are so resilient, he has redoubled his efforts.
“I don’t think we own the copyright to the super corals of Vega Baja,” he says. “It would be nice to help more people.”
