Jeff Berardelli is a climate specialist and the Chief Meteorologist at News Channel 8.
On Monday at about 5 p.m, a water temperature gauge in Florida Bay, just south of Everglades National Park and north of the Florida Keys, registered an astonishing 99.3 degrees. At the time, that appeared to be the hottest temperature ever recorded in this area.
But then, just after 7 p.m., there was a buoy just north of Key Largo called Manatee Bay that registered 100.1F. Just as is the case in Murray Key, the observation is measured around 5 feet below the surface.
Then, at about 7:30 p.m., water temperatures in at Manatee Bay registered at 101F. Ordinarily meteorologists would assume the gauge was broken, but at least 3 sites in the region registered 98 or greater today, so this adds some credibility. And this comes amidst weeks of record breaking water temperatures in Florida Bay and the Keys.
The images below show the data from the NOAA station. If verified this may challenge the World record for hottest sea surface temperature of 99.7F in Kuwait Bay. Still, NOAA will need to certify this and I imagine, given water conditions there it may not qualify. We will see.
These sites are in shallow, murky, dark water so they absorb the sun’s radiation very well. And the temperature goes up and down very quickly based on how sunny it is. Therefore they often show elevated temperatures as opposed to deeper sites where water is more clear. It does not mean the observations are wrong, it is just a characteristic of the water there.
However, a paper published in 2009 – admittedly a while back – claims that some of these shallow water sites may suffer from contamination which can lead to the sensors being off by 1 degree C or less. A small snippet of this paper can be found here. So, it is important to mention that it’s plausible the stations temperatures may be slightly overdone. Still upper 90s is off the charts.
This comes at a time when the remaining Keys coral is under onslaught from a fierce marine heatwave. Since the 1970s, coral cover in the Florida Keys has fallen from nearly 40% to less than 3 %. And right now coral are rapidly bleaching and dying in parts of the Keys as the record heat continues.
Average sea surface temperatures in the Keys region are now in the low 90s. The normal is near 85. Even bottom temperatures are near 90 degrees.
There are numerous coral reef restoration projects ongoing in the Florida Keys. But unfortunately, at the moment, the battle is being lost to the relentless heat with widespread mortality reported on the restoration sites.
Heat stress has been ongoing for nine weeks in the Keys, with NOAA’s Coral Reef Watch program declaring an Alert Level 2, the highest alert for bleaching.
With the typical peak of summer water temperatures still a few weeks away, it looks as though coral will have to endure many weeks more of deadly heat.
Various coral restoration teams are busy saving corals, by taking them out of the ocean and bringing them to faculties to keep them cool until they can be returned to the ocean.
While a persistent weather pattern of light winds and sunshine can be partially blamed, underlying this is human-caused climate change from the burning of fossil fuels.
Water temperatures have warmed 2 degrees F in the Atlantic over the past few decades and warming rates are twice as fast in the Gulf of Mexico as the global average. This is due to both greenhouse warming and the reduction in atmospheric pollution over the Atlantic basin, allowing more sunlight in.
It’s plausible, that by summer’s end, most of the Florida Keys coral will be wiped out. And by 2050 scientists estimate that 95% or more of tropical corals will wiped out. That is unless we quickly reel in carbon pollution or find heat resistant coral hardy enough to survive climate heating’s relentless onslaught.