Kategorie: News
Thousands of corals brought to safety
As rising sea temperatures take their toll on the coral reefs of the Florida Keys, scientists and conservationists have begun a race against time – the survival of entire coral species is at stake.
In early July 2026, the US National Oceanic and Atmospheric Administration (NOAA) officially declared a ‘Level 1 alert’ for coral bleaching in the Florida Keys. In practice, this means that water temperatures are already so high that corals are in mortal danger. And summer has only just begun.
When the sea turns into a hot bath
Corals like it warm – but not too warm. When temperatures remain high for prolonged periods, these fascinating marine organisms expel the tiny algae that live within them and supply them with nutrients. This process, known as coral bleaching, leaves the corals bleached and unwell. They can survive like this for a few weeks, starved and, in a sense, ‘sunburnt’. If the water cools down in time, they recover. However, if temperatures remain too high for too long, many corals die.
The year 2023 showed just how devastating such heatwaves can be. At that time, the waters off Florida reached the highest temperatures ever recorded in modern history. The consequences were catastrophic: coral reefs turned into veritable graveyards. Two coral species have since been deemed ‘functionally extinct’ – they still exist, but in such small numbers that natural recovery seems virtually impossible.
A menacing repeat in 2026?
The latest data gives cause for grave concern. “Level 1 alert doesn’t do the situation justice. It’s frightening; it’s extreme,” says Ken Nedimyer, technical director of the conservation organisation Reef Renewal USA. “We’re heading towards a year that could be even hotter than 2023.”
In fact, NOAA measurements show that sea surface temperatures are already matching the record pace set in 2023 – and in some cases even exceeding it. The El Niño phenomenon, which is resulting in fewer hurricanes this year, is simultaneously causing the waters to warm up even further.
In response to the NOAA warning, coral rescue organisations immediately launched emergency measures. The Coral Restoration Foundation has already moved 246 corals – including particularly endangered moose-antler and stag-antler corals – to safety in land-based refuges. Further evacuation stages are in place should the situation worsen.
Nedimy’s team set off by boat to their underwater nurseries, where they breed young corals. Their aim: to bring 400 elk-antler and stag-antler corals to safety. Some will be relocated to deeper, cooler waters, whilst others will be moved to temperature-controlled tanks in West Palm Beach and Tampa. A further hundred larger corals are due to follow in the coming week.
A desperate race against time
However, the largest corals – some with a diameter of over a metre – remain in the sea. The reason is a glimmer of hope: scientists expect these corals to spawn in the first week of August, that is, to produce their offspring. If they can hold out that long.
These very corals are representatives of the species that researchers have already classified as ‘functionally extinct’ in Florida. ‘They are the most threatened,’ explains Nedimyer. ‘They are teetering on the brink of extinction. They are hanging by a thread.’
The rescuers’ plan is just as simple: they want to collect the spawn – the microscopic coral babies – and transfer them to the cooler, safer waters of their laboratory tanks. There, they will grow into fully-grown corals that can later be reintroduced to the reef.
Surprisingly, in 2023, scientists observed that even completely bleached corals continued to spawn. This gives the researchers hope that they might still be able to save one more generation of these endangered species – even if water temperatures rise to hot-tub levels.
“This could be their last gasp,” says Nedimyer matter-of-factly. “No matter what we do, we might end up losing many of them. We’re doing everything in our power. We’re trying to spread the risk as much as possible.”
Learning from disasters
Phanor Montoya-Maya, programme director at the Coral Restoration Foundation, emphasises that the devastating year of 2023 taught conservation organisations important lessons. These experiences are now helping them to respond more effectively to heatwaves such as the current one.
“Despite significant losses, thanks to years of experience in coral restoration, we were able to save more than 17,000 coral colonies across 23 different species,” reports Montoya-Maya. “We’re monitoring conditions closely, and we’re better prepared this year – thanks to everything 2023 taught us.”
What is at stake
Coral reefs are far more than just colourful underwater landscapes. They provide a habitat for around a quarter of all marine life, even though they cover less than one per cent of the ocean’s surface. They protect coastlines from storm surges and erosion, and provide a livelihood for millions of people worldwide through fishing and tourism. Their ecological and economic value is almost impossible to quantify.
The coral reefs off Florida are among the northernmost in the world and form the only living barrier reef in the continental United States. Their loss would not only be an ecological disaster, but would also have dramatic consequences for the region’s economy and coastal protection.
Rising sea temperatures are a direct consequence of climate change. Whilst individual heatwaves, such as those of 2023 and possibly 2026, are exacerbated by natural phenomena such as El Niño, the underlying warming trend is man-made. Over the past few decades, the oceans have absorbed over 90 per cent of the additional heat generated by the greenhouse effect.
For corals, which are adapted to relatively narrow temperature ranges, this means increasing stress. Experts warn that such bleaching events, which used to occur every few decades, could now happen almost every year.
A race that must not end
The work of the coral rescuers in Florida impressively demonstrates how dedicated scientists and conservationists are battling against seemingly overwhelming forces. With every coral polyp saved, with every successful breeding programme, they are not only saving species from extinction but also preserving the hope of a future in which the reefs can recover.
Yet the rescuers also know that their work can only buy time. The long-term solution lies not in underwater evacuations, but in tackling the root causes – global warming.
As long as sea temperatures continue to rise, every summer becomes a potential death sentence for the corals.
“We’re fighting on two fronts,” sums up a marine biologist who wished to remain anonymous. “We’re saving what can be saved, and at the same time we’re hoping that the world will finally wake up and take action before it’s too late.”
Outlook: Between hope and reality
The coming weeks will show whether temperatures remain moderate or continue to rise. Whether the rescued corals will actually be able to spawn in August. Whether another generation of these ancient creatures will have a chance.
The coral rescuers will continue their work – with the perseverance of people who know that giving up is not an option. But they also know that their efforts alone will not be enough. The future of the coral reefs ultimately lies in the hands of us all.
Further information:
Coral Restoration Foundation
Floridas Coral Reefs
NOAA