🔗 Share this article Two Vital Florida Coral Species Deemed 'Functionally Extinct' Following Severe Ocean Heatwave Scientists have discovered that two of the key coral species forming Florida's reef are now functionally extinct following a intense ocean heatwave caused catastrophic losses. The Meaning Behind 'Functional Extinction' Signifies The near-total decline of these corals, which once served as the backbone of reefs in Florida and the Caribbean, means they can no longer fulfill their previously crucial role in constructing and maintaining reef ecosystems that support a diversity of marine life. Functional extinction is a stage before total extinction, a danger that now looms for many coral species. Scientists this month warned that a critical threshold had been reached, whereby corals globally are set to be wiped out due to climate change, which is increasing ocean temperatures to unbearable levels. Researcher Insight "We're running out of time," stated Ross Cunning of the recent research. "Extreme heatwaves are increasing in frequency and severity due to climate change, and absent immediate, ambitious actions to slow ocean warming and enhance coral survival, we face the danger of the extinction of additional coral species from reefs in Florida and worldwide." The Recent Study The recent study, published in the journal Science, analyzed the outcome of staghorn coral and elkhorn corals off the Florida coast after a severe marine heatwave in 2023. This event raised temperatures on Florida's fraying coral reefs to their highest levels in over 150 years. The two species are complex, reef-forming corals and are identified because they resemble, in turn, the antlers of stags and elk. However, researchers who performed diver surveys of more than 52,000 colonies of the species, across nearly four hundred sites along Florida's coast, found extensive, often devastating, losses. Regional Effects Along the Florida Keys, death rates hit 98% and even 100%, showing a total eradication of the corals. In southeastern Florida, where temperatures have been lower, mortality rates were lower, at about thirty-eight percent. Historical and Current Dangers The two Acropora species had already endured from many years of localized impacts in Florida, such as poor water quality from pollutants that wash off the land, as well as illness. But the 2023 heatwave has been lethal for these heat-sensitive species. The 2023 event caused the ninth occurrence of coral bleaching on the Florida reef – a phenomenon whereby corals become heat-stressed and expel the algae partners 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 at risk to the anthropogenic climate crisis. This poses a major threat to: One-fourth of all ocean life that depends on what are essentially the rainforests of the sea. Hundreds of millions of people who rely on corals to sustain fish that they can eat and gain an income from. Corals also act as a barrier to safeguard our shorelines from intense hurricanes, which are themselves being intensified by increasing global heat. Preservation Efforts In a desperate attempt to prevent a death spiral of endangered corals, scientists have established repositories of Acropora in aquariums and offshore coral nurseries. Attempts have been undertaken to reseed corals on reefs in Florida, as well, in an effort to regain some of the ninety percent of coral cover disappeared off the state in the past four decades. But as climate change continues to intensify, there is slim chance of continued existence of these species absent major interventions, researchers warn. Additional Researcher Insight "Elkhorn corals, especially, are some of the most important wave-dampening coral species in the area," said a study co-author, a marine biologist at the Miami University. "They were once common on shallow reef tops in the Caribbean, and if we want our reefs to continue protecting our coastlines from flooding during storms, its worth taking extraordinary measures to ensure we preserve these corals completely."