🔗 Share this article A Pair of Crucial Florida Coral Species Deemed 'Functionally Extinct' Following Severe Ocean Heatwave Researchers have found that two of the key coral species comprising Florida's reef have become functionally extinct after a withering ocean heatwave led to catastrophic losses. The Meaning Behind 'Functional Extinction' Signifies The almost complete collapse of these corals, which once served as the backbone of reefs in Florida and the Caribbean, means they are no longer able to play their once vital role in building and sustaining reef ecosystems that host a variety of marine life. Ecological extinction is a stage preceding global extinction, a danger that now hangs for many coral species. Researchers recently alerted that a tipping point had been reached, whereby corals globally are set to be eradicated due to climate change, which is raising ocean temperatures to intolerable levels. Researcher Insight "Time is running out," said the lead author of the recent research. "Extreme heatwaves are becoming more frequent and intense due to global warming, and absent swift, decisive measures to reduce ocean heating and boost coral resilience, we risk the extinction of additional coral species from reefs in Florida and worldwide." The New Research The new research, featured in the Science journal, examined the fate of staghorn coral and elkhorn corals off the Florida coast after a intense marine heatwave in 2023. This event elevated temperatures on Florida's deteriorating coral reefs to their highest levels in over 150 years. The two species are complex, reef-forming corals and are identified because they look like, in turn, the horns of stags and elk. However, researchers who performed diver surveys of over fifty-two thousand colonies of the species, across 391 sites along Florida's coast, found widespread, often devastating, losses. Geographic Effects In the Florida Keys, mortality rates hit 98% and even one hundred percent, revealing a total eradication of the corals. In southeastern Florida, where temperatures have been cooler, death rates were lower, at about thirty-eight percent. Past and Current Threats The two Acropora species had already suffered from many years of localized impacts in Florida, such as contaminated water from pollutants that wash off the land, as well as illness. But the 2023 heatwave has proved fatal for these heat-sensitive species. The 2023 event caused the ninth occurrence of bleaching on the Florida reef – a phenomenon whereby corals become heat-stressed and eject the symbiotic algae living in their tissues, causing them to become ghostly white. If temperatures remain elevated, the corals die off completely. Worldwide Consequences Globally, coral reefs are among the ecosystems most vulnerable to the anthropogenic climate crisis. This poses a major threat to: A quarter of all ocean life that relies upon what are essentially the marine rainforests. Hundreds of millions of people who depend upon corals to sustain fish that they can eat and earn a livelihood from. Corals also act as a protective barrier to protect our shorelines from powerful storms, which are themselves being worsened by increasing global heat. Preservation Attempts In a desperate attempt to avert a death spiral of endangered corals, scientists have created repositories of Acropora in aquariums and ocean-based nurseries. Efforts have been undertaken to replant corals on reefs in Florida, as well, in an effort to regain some of the 90% of coral cover disappeared off the state in the last forty years. But as global heating continues to intensify, there is slim chance of continued existence of these species without major interventions, scientists caution. Further Expert Commentary "Elkhorn species, especially, are some of the most important wave-breaking coral species in the area," noted a study co-author, a marine biologist at the Miami University. "They used to be common on shallow reef crests in the Caribbean, and if we want our reefs to continue protecting our coastlines from inundation during storms, its worth taking extraordinary measures to ensure we don't lose these corals completely."