In Florida, a race against time is on: coral rescue operations are multiplying to preserve these animals which are resisting very badly to the unprecedented warming of the ocean caused by the heat wave in the south of the United States.
In the Florida Strait, the water temperature regularly exceeds 32°C. On Monday, it even reached 38.3°C in Manatee Bay, an absolute record.
Day after day, therefore, members of the Coral Restoration Foundation take to the seas and brave scorching temperatures outside to reach the reefs and dive to deep-sea coral nurseries to collect specimens for safe in laboratories.
They deposit them there in tanks maintained at a temperature varying between 21 and 28.8ºC, the acceptable range for corals, explains Alex Neufeld, logistics manager at the foundation.
Urgent action because this unusual heat stresses the corals, which thereby expel their zooxanthellae — algae living in symbiosis with them which provide them with the nutrients they need.
And by expelling them, they also lose their color: we then speak of coral bleaching, the harbinger of their certain death if nothing is done quickly.
However, in recent weeks, the phenomenon has been massive: “I have never seen anything worse (…) This could potentially become the most serious (episode of bleaching) in the history of the Keys”, an archipelago off from Florida, adds Alex Neufeld. The last event of this magnitude dates back to 2014.
Florida’s barrier reef is one of the longest in the world: it stretches over 500 km, hugging the curve of the coast, which it runs along from the north, near Saint Lucia, to at its southern end and the archipelago of the Keys.
Its role is essential on many levels: it is a marine biodiversity reserve, a refuge for wildlife, but also a bulwark against hurricanes and high tides.
“What has been happening for several weeks is terrible, impressive. I wanted to cry when I went diving”, laments Brian Branigan, owner of a company which rents boats in the archipelago, to Big Pine Key.
Brian Branigan took AFP to Looe Reef, some 10km offshore, where you can spot barracuda, parrotfish…and fading coral.
“This too hot water is not good for any marine species: neither for corals, nor for fish or lobsters”, explains Alex Neufeld. “The risk is that there will be a hecatomb of fish, sea turtles…”
And the worst, he adds, is that summer still has good days ahead of it.
Therefore, “over the past two weeks, we have taken samples from all the species and all the genetic strains that we work with,” he says.
The corals collected by several NGOs, including his own, are notably deposited in the marine laboratory of the Florida Oceanographic Institute, where they will be preserved in seawater tanks until the temperature becomes bearable again. The good news is that a coral that has bleached can still be saved.
At the same time, the NGO monitors the reefs to identify sites that are more resistant, where it will no doubt choose to relocate corals in the future.
Meanwhile, Captain Branigan worries.
Not only does this silent catastrophe hurt him because he has a sentimental attachment to these crystal clear waters where he learned to dive almost half a century ago, but it could also cause his financial loss.
Because the wonders of the archipelago provide a full or part-time livelihood for some 70,400 professionals – fishermen, divers, guides – whose income represents two billion dollars each year.
“We are worried personally and financially. And I am convinced that all of this will have negative, even catastrophic consequences,” he says.
In Florida, several NGOs have also been mobilizing for years to save corals, in particular by seeking to develop species with a particularly resistant genotype.
29/07/2023 10:56:20 – Summerland Key (Etats-Unis) (AFP) – © 2023 AFP
