Florida's coral reef system could be lost forever due to climate change
The great Florida coral reef system could be lost forever due to climate change, according to new research.
Warming seas are driving marine life to shift their geographic ranges to higher latitudes.
But those living off the coast of the idyllic southern state won’t even be able to make that move.
They are being caught between intolerably hot tropical waters and increasingly frequent cold snaps, say scientists.
Lead author Dr Lauren Toth, of the US Geological Survey in St Petersburg in Florida, said: ‘It’s just not as simple as predicting the corals will move north.
‘Thousands of years ago, corals and coral reefs moved north along Florida’s east coast when the climate warmed, but things are different now.
‘Rapid climate change looks to be increasing the number of cold fronts from the polar vortex that are dipping down into Florida.’
The warning follows calls from Unesco to have the Great Barrier Reef put on a list of World Heritage Sites ‘in danger’ due to climate change.
Florida’s is the world’s third largest – stretching 350 miles down the eastern seaboard of the US.
Nearly 1,400 species of plants and animals and 500 species of fish have been recorded there.
They include the threatened green sea turtle, West Indian manatee and smalltooth sawfish.
Spiny lobster, snapper and grouper find shelter, food and breeding sites in coral reefs.
They support 70,000 jobs and are worth an estimated $8.5 billion to the US economy.
Florida is home to 400,000 British ex-pats. The UK is second only to Canada as the origin of overseas visitors with 1.5 million visitors a year.
Corals are colonies of animals related to sea anemones. They lay down limestone to make reefs that protect shorelines from storm waves.
They provide habitat for fish that feed half-a-billion people globally. They are fed by single celled algae that live inside.
The microscopic creatures make carbohydrates from photosynthesis. They are already in dire condition – and listed as endangered.
The study in Scientific Reports shows with no where to go corals will decline even more drastically than feared.
Climate change is raising temperatures and disrupting the tight, symbiotic relationship – to the point reefs are vanishing all over the world.
One common prediction is they will simply migrate north – and re-appear where the water is cooler.
For instance, staghorn coral – a major constructor of Caribbean reefs – has recently begun to grow north of Miami as the climate has warmed.
But its prospects for building reefs that far north will be severely limited by cold fronts – which climate change is making more common.
More regular freezes in Florida will prevent their re-establishment away from the tropics.
Co-author Dr Richard Aronson, a marine scientist at Florida Tech, said: ‘All of us on the Eastern Seaboard know the jet stream is wobbling more and dipping southward more frequently – bringing us bad winter storms and bitterly cold weather.
‘The corals along Florida’s east coast will be hammered from the north by freezes on the anvil of rising temperatures in the south.
‘They won’t be able to shift locations from the Florida Keys to the east coast.’
Co-author Dr William Precht, a marine biologist at consultants Dial Cordy and Associates Inc in Florida, said there are serious implications.
They go beyond corals’ essential ecological importance to people’s financial and physical wellbeing.
He said: ‘That is a very obvious reason why Floridians – and everyone else for that matter – should be concerned about the impacts of climate change on corals.’
Overfishing, development and pollution have all contributed to the Florida reef’s decline – but climate change is its biggest threat.
Recent research suggests its halved in size since the industrial revolution – and its disappearance is speeding up.
Fishing off the Florida Keys has intensified and roads and cities have been built.
This has increased pollution and altered the flow of freshwater, sediments and nutrients from the land all changed.
Experts say UN targets to hold temperature rises to 1.5C must be met. If the oceans continue to absorb CO2, bleaching will worsen.
Corals are intolerant both of temperature and salinity change. It takes a rise of only 1C for a few weeks or extreme rainfall for them to die.
Last year a study warned coral reefs around the world could disappear by 2100 as the ocean’s get hotter and more acidic.
It would spell the end of the Great Barrier Reef – one of the seven natural wonders of the world.
On Monday Unesco, the UN’s cultural body, urged Australia to take ‘accelerated action’ to save it.
Several bleaching events in the past five years have caused widespread loss of coral.
But the country, a large exporter of coal and gas, is reluctant to commit to stronger action.
Its government is resisting pressure to sign up to a net zero emissions target by 2050.
If the reef is downgraded, it will be the first time a natural World Heritage Site has been placed on the ‘in danger’ list through climate change.
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