The marine heat wave is killing coral reefs. Here's how South Florida is being impacted

South Florida’s coral reefs are in grave danger and the enemy is the water in which they live — It’s just way too hot.

“We’re now in the middle of July and we’re looking at temperatures higher than we’ve ever seen before and this includes late summer, August, September, so we are on target for hitting temperatures that we’ve never seen before in South Florida waters,” said Bill Precht, a coral researcher formerly with NOAA. 

The high temperatures cause corals to bleach, which means they lose the symbiotic algae which give them their color. 

“So right now we’re on track for corals to bleach this summer and bleach for a longer period than they’ve ever bleached before which will likely lead to high levels of coral mortality,” Precht explained. 

“It’s really concerning because these high temperatures are just one more stressor on top of all the other stressors our reefs face here in Florida,” said Dr. Abigail Renegar, a coral researcher at Nova Southeastern University. “I’m very worried.”

Renegar’s team of scientists has recorded temperatures recently in the high 80s as deep as 70 feet under the surface. Combined with the ravages of stony coral tissue disease and pollution from storm water runoff, Florida’s reefs keep taking punches, wave after wave. 

“It’s a very grim forecast and somebody asked me the other day, well what can we do about it now? And right now today, there’s nothing we can do about it, it’s like if a hurricane was coming in our direction, there’s nothing we physically can do to stop that hurricane from coming,” said Precht, who’s been studying corals for 45 years. 

In other words, nothing humans can do will cool off the water in the short term. Scientists, however, are using genetic engineering to develop corals which can tolerate higher water temperatures

“They are, but the question is how many, and how can they scale that up? And that’s the question for the future, the question for summer of 2023 is, how bad is it gonna get?” Precht said. 

Coral reefs pump an estimated $7.5 billion into the South Florida economy. So how bad will the hit be to ecotourism and the fishing industry, which depend on healthy reefs?

“It’s a 1,2,3 punch that is devastating both ecologically and economically,” Precht said. 

There’s no relief in sight. Fueled by climate change and El Nino, the waters keep heating up. 

“That’s certainly what temperature trends show, is that temperatures are increasing constantly, we just don’t know how fast the corals can adapt to those increases in temperature,” Renegar said.