🔗 Share this article A Pair of Vital Florida Coral Species Deemed 'Functionally Extinct' After Severe Ocean Heatwave Scientists have discovered that two of the key coral species forming Florida's reef are now functionally extinct following a withering ocean heatwave caused devastating losses. The Meaning Behind 'Functional Extinction' Means The almost complete decline of these corals, which once formed the backbone of reefs in Florida and the Caribbean, indicates they can no longer fulfill their previously crucial role in building and sustaining reef ecosystems that host a diversity of marine life. Functional extinction is a phase before global extinction, a threat that now hangs for many coral species. Researchers this month alerted that a tipping point had been reached, meaning corals globally are set to be wiped out due to global heating, which is increasing ocean temperatures to unbearable levels. Expert Insight "We're running out of time," said the lead author of the recent research. "Severe marine heatwaves are becoming more frequent and intense due to climate change, and absent swift, decisive measures to slow ocean warming and boost coral resilience, we risk the extinction of additional coral species from reefs in Florida and worldwide." Details of the Recent Study The new research, published in the journal Science, examined the outcome 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 peak temperatures in more than a century and a half. The two species are complex, reef-building corals and are identified because they resemble, respectively, the antlers of stags and elk. However, researchers who performed diver surveys of more than 52,000 colonies of the species, across 391 sites along Florida's coast, found extensive, often catastrophic, losses. Regional Impact Along the Florida Keys, mortality rates reached 98% and even 100%, revealing a total eradication of the corals. In southeastern Florida, where temperatures have been lower, death rates were lower, at about 38%. Past and Present Threats The two Acropora species had already endured from decades of localized impacts in Florida, such as contaminated water from contaminants that wash off the land, as well as illness. But the 2023 marine heatwave has been fatal for these heat-sensitive species. The 2023 event caused the ninth episode of 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 die off entirely. Global Consequences Globally, coral reefs are among the ecosystems most at risk to the human-caused climate crisis. This presents a significant danger to: One-fourth of all ocean life that depends on what are effectively the rainforests of the sea. Millions of people who rely on corals to support fish that they can consume and earn a livelihood from. Corals also act as a protective barrier to safeguard our shorelines from intense hurricanes, which are themselves being worsened by increasing global heat. Preservation Attempts In a desperate attempt to prevent a decline of endangered corals, scientists have established repositories of Acropora in marine facilities and ocean-based nurseries. Efforts have been made to replant corals on reefs in Florida, as well, in an effort to restore some of the ninety percent of coral cover lost 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 absent major interventions, researchers warn. Additional Researcher Insight "Elkhorn corals, in particular, are some of the key wave-dampening coral species in the region," noted Andrew Baker, a ocean scientist at the Miami University. "They were once common 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 extraordinary measures to ensure we preserve these corals altogether."