🔗 Share this article Two Vital Florida Coral Species Declared 'Functionally Extinct' Following Severe Ocean Heatwave Scientists have discovered that two of the most important coral species comprising Florida's reef have become functionally extinct following a withering ocean heatwave led to catastrophic losses. The Meaning Behind 'Functional Extinction' Means The almost complete decline of these corals, which once served as the backbone of reefs in Florida and the Caribbean, indicates they are no longer able to fulfill their once vital role in building and sustaining reef ecosystems that support a diversity of marine life. Ecological extinction is a phase before total extinction, a danger that now hangs for many coral species. Researchers this month alerted that a tipping point has been crossed, meaning corals globally are set to be eradicated due to global heating, which is raising ocean temperatures to unbearable levels. Researcher Perspective "We're running out of time," stated Ross Cunning of the new Florida study. "Severe marine heatwaves are increasing in frequency and severity due to global warming, and absent swift, decisive measures to slow ocean warming and enhance coral survival, we risk the disappearance of additional coral species from reefs in Florida and around the world." Details of the New Research The new research, featured in the journal Science, examined the fate of staghorn coral and elkhorn corals off the Florida coast following a severe marine heatwave in 2023. This event raised temperatures on Florida's deteriorating coral reefs to their highest levels in more than a century and a half. The two species are complex, reef-building corals and are identified because they look like, in turn, the horns of stags and elks. However, researchers who conducted diver surveys of over fifty-two thousand colonies of the species, across nearly four hundred sites along Florida's coast, found widespread, often catastrophic, losses. Geographic Impact In the Florida Keys, mortality rates reached ninety-eight percent and even 100%, revealing a complete annihilation of the corals. In south-east Florida, where temperatures have been cooler, death rates were reduced, at about 38%. Past and Current Dangers The two Acropora species had already endured from many years of localized impacts in Florida, such as contaminated water from contaminants that wash off the land, as well as disease. But the 2023 heatwave has been lethal for these heat-sensitive species. The 2023 heat event caused the ninth episode of coral bleaching on the Florida reef – a phenomenon whereby corals become heat-stressed and expel the symbiotic algae living in their tissues, causing them to become bleached white. If temperatures remain elevated, the corals perish completely. Worldwide Consequences Globally, coral reefs are among the ecosystems most vulnerable to the anthropogenic climate crisis. This poses a significant danger to: A quarter of all ocean life that relies upon what are essentially the marine rainforests. Millions of people who depend upon corals to sustain fish that they can eat and gain an income from. Corals also serve as a protective barrier to safeguard our shorelines from intense hurricanes, which are themselves being intensified by rising global temperatures. Preservation Efforts In a desperate attempt to avert a death spiral of threatened corals, scientists have created repositories of Acropora in aquariums and offshore coral nurseries. Attempts have been made to replant corals on reefs in Florida, as well, in an effort to restore some of the 90% of coral cover lost off the state in the past four decades. But as climate change continues to escalate, there is slim chance of long-term survival of these species without significant actions, researchers warn. Further Researcher Insight "Elkhorn species, in particular, are some of the most important wave-breaking coral species in the region," said Andrew Baker, a marine biologist at the University of Miami. "They used to be abundant on shallow reef crests in the Caribbean, and if we want our reefs to keep safeguarding our coastlines from inundation during storms, its worth taking exceptional steps to ensure we preserve these corals altogether."