WASHINGTON – Just off the southeastern tip of the United States, you’ll find an underwater masterpiece: the only barrier reef in North America. But rising ocean temperatures are disrupting this once dynamic ecosystem.
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- Rising ocean temperatures have killed around 14% of the world’s corals in the past decade, new study finds
- In Florida, home to the only barrier reef in North America, only about 2% of the original coral cover remains.
- Experts say climate change has played a big role in coral loss, but things like disease, pollution and development are also contributing to the problem
Rising ocean temperatures have killed around 14% of the world’s coral reefs in just under a decade, according to a new study from the Global Coral Reef Monitoring Network.
In the United States, the majority of losses occur along the Florida coast, where only 2% of the original coral cover remains.
âI think we’re all pretty used to knowing that we’re going to see more losses in the future,â said Jennifer Koss, director of the National Oceanic and Atmospheric Administration (NOAA) coral reef conservation program.
The water temperature has risen by 1.4 degrees Fahrenheit since 1970. Koss said that even a slight increase in the water temperature is dangerous because the corals become stressed and expel the algae that live in them – a process known as bleaching.
âCorals don’t necessarily die at this point, but the longer they live without this algae, the more likely they are to die,â Koss said in an interview with Spectrum News. “If the water temperature drops, then the corals can re-recruit the algae, they can withstand a bleaching event. When the temperatures persist for too long, we see massive mortalities.”
But bleaching is only one of the factors leading to the loss of coral in this area. A mysterious disease outbreak, first observed in 2014, has proven to be even more deadly.
âWe have never seen a disease like this before. To go that fast with such mortality, âKoss said.
The disease, known as stony coral tissue loss, can infect and kill entire coral heads within days. Infection causes coral tissue to break down and shed, bleaching reefs as they die.
“We often talk about death by a thousand cuts,” said Karen Neely, coral ecologist at Nova Southeastern University. âThis includes climate change, changes in water quality, even small things like anchoring on a reef. The disease of stony coral tissue loss is the last and most important cut, but it is not the only one. ”
The cause of the illness has not yet been determined, but Neely suspects it is bacterial and spread in water. But warming seas, pollution, development and climate change may also have been contributing factors.
âIt’s very difficult with coral diseases to even identify what causes them,â said Neely.
Spectrum News saw firsthand how the disease progresses on the water with researchers two years ago. Since then, the disease has spread to all reef sites in the Florida Keys, including Dry Tortugas National Park.
âThe Tortugas were disease free until early June of this year,â said Neely.
Neely and a small group of scientists have deployed one of the most unusual medical interventions in recent history. Over the past two years, the team has applied antibiotic goop to thousands of coral colonies infected with the disease.
âWe have high efficiency there, 90-95% excess,â Neely said. “There are examples where the colonies will be re-infected and so we go back to a lot of those colonies and do medicals if they have new legions of diseases, we treat them accordingly.”
Throughout 2020, Neely and her crew continued their work of processing coral. But, she says, the above-surface pandemic has halted much of their research.
âOne of the reasons is that many labs that analyze samples like this have been redirected to COVID samples,â she said.
For coral in Florida waters, there is virtually no escape from climate change.
âFor anyone who dives and sees our reefs, no one ever comes back and says it looks better than before, still looks worse than before,” said Neely.
Yet amidst a sea of ââbad news, there is a glimmer of optimism.
“Thanks to sound research and management actions, we see few glimmers of hope,” said Koss. “We really hope that we can maintain enough species and diversity among living species, that with more care, corals will persist into the future.”