Extreme heat in South Florida could spell disaster for Biscayne Bay, local coral reefs

MIAMI-DADE COUNTY, Fla. – Florida has been sizzling in record, crushing heat, and it is already having destructive impacts on our local ecosystems.

It’s not just the atmosphere, but prematurely high water temperatures are concerning scientists who are monitoring extreme weather events happening all over the planet.

Marine scientist Colin Foord headed to the shore at Crandon Park Beach on a particularly sweltering July morning.

“Incredible,” he said. “The water keeps getting warmer and warmer.”

He is extremely worried about the unrelenting triple-digit heat indices that for more than a month have been smothering South Florida.

“I don’t think we’ve seen this type of early heating this early in the year ever in recorded history,” Foord said.

Foord is a coral biologist and the co-founder of Coral Morphalogic, which hosts the Coral City Cam at Port Miami.

Even for the super resilient urban corals that thrive in Government Cut, the recent surface temperatures are deadly.

“It’s 94 degrees Fahrenheit and this water here, 94 degrees, is just extremely hot,” said Foord. “No marine life is going to be happy or healthy in water that is that hot.”

Corals begin to stress out when water temperatures exceed 86 degrees.

In fact, Foord said that some of the reefs in the Florida Keys are already experiencing bleaching, which is when an ocean that’s too warm causes corals to flush out the life-giving algae’s in their tissues, turning them white.

“When a coral is bleaching, it is starving, it loses its access to the sunlight,” said Foord. “The way a plant is able to photosynthesize, a coral can no longer photosynthesize, and basically it’s got to live off of its fat reserves. And if that goes on until September, October, unfortunately we could be looking at a massive coral die off here in South Florida.

That’s concerning, because Florida’s barrier reef has already lost more than 90% of its coral cover, and with temperatures this high so early on in the summer, Foord fears it could spell disaster.

“It means if bleaching starts now, in early July, it means that by October, those corals are probably going to be dead,” he said.

That would be devastating to the Sunshine State.

According to NOAA, Florida’s coral reefs represent $8.5 billion annually in assets, tourism dollars and jobs, and they help protect our coastlines from catastrophic storm surge during hurricanes.

For climate activists, this is yet another loud alarm that our planet is on fire.

“Our planet is screaming, our planet is telling us, you’re putting too much carbon pollution into my atmosphere, and you are facing the consequences,” said Yoca Arditi-Rocha, Executive Director of The CLEO Institute.

Arditi-Rocha underscores the need to act with more urgency.

Though we’re starting to see clean renewable energy being scaled to rapidly decarbonize our economy, she says we’re not doing it fast enough.

“We need to reduce the amount of carbon pollution that is warming, actually cooking our planet as we speak,” said Arditi-Rocha.

Biscayne Bay is also on the burner.

At FIU’s Institute of Environment, students and scientists are keeping a close eye on the bay, as with corals, these extremely high temperatures can trigger another disaster for the fragile watershed.

“If the bay is quiet, and it gets very, very hot, yes we could have some problems,” said Dr. Piero Gardinali with the FIU Institute of Environment.

In August of 2020, Biscayne Bay experienced an unprecedented fish kill, with over 27,000 marine animals suffocating to death in the northern basin.

It was a depletion of oxygen in the water column caused by too much pollution, no tidal flow, and scorching temperatures.

“We are hovering between 31 and 32 degrees Celsius since the fish kill happened, when we were about 36 degrees Celsius and a little bit above that, so we need to keep an eye on it,” said Gardinali.

Four research buoys stationed in different locations in the bay provide real time data for 24-7 monitoring, measuring water temperature, dissolved oxygen levels, salinity and other important metrics.

“What we’re trying to do is create that early warning system,” said Gardinali.

But it’s only July and scientists believe we’re already in the grips of the hottest year on record.

“It’s almost like our planet has a fever,” said Foord. “And you know, when we get a fever, our whole body gets out of whack. And sadly, that’s what we’re seeing across all of these ecosystems all around the planet.

“It’s really a global problem. But we’re seeing the local impacts right here in our own backyard.”

Miami has already spent more time in 2023 above a 105-degree heat index than it ever has in any recorded year.

Since mid-June, weekly water temperatures across the Gulf of Mexico have reached record levels and the Gulf is the warmest it’s been ever.

The Midwest and Western Europe are also in the grips of a heat wave as scientists all over the planet hold their collective breath and watch what happens.

If you’d like to monitor the real-time data coming in from the FIU research buoys, click here.

About the Author:

Louis Aguirre is an Emmy-award winning journalist who anchors weekday newscasts and serves as WPLG Local 10’s Environmental Advocate.