A picture of staghorn and fire coral taken in July 2023 off Key Largo, bleached white against the blue water, is making the rounds among marine scientists. Skeletal and stark. It appears to have been dead for a very long time. Two weeks prior to the photo being taken, it was still alive.
You can learn more about what’s going on in the Florida Keys from that picture, which was taken by University of Miami researchers, than most press releases will acknowledge. The third-largest barrier reef system in the world, the Great Florida Reef, is dying. not decreasing on a graph. not showing signs of stress. dying in quantifiable, observable, and progressively irreversible ways.
Nearly 90% of the live coral that formerly covered these reefs has vanished in the last 40 years. In the early 1980s, entire reef zones made up of city-block-sized patches of elkhorn and staghorn corals have been reduced to sporadic fragments. Graduate students are now drawn to view desk-sized patches, according to one researcher. You have that particular detail.
Everything picked up speed in the summer of 2023. Ocean temperatures in the Florida Keys reached record highs as a result of a marine heat wave that began in February and swept through the Caribbean and Gulf of Mexico. A Level 2 bleaching alert was issued by NOAA. When corals are subjected to prolonged heat stress, the algae that give them color and the majority of their energy are forced out of their tissue, causing coral bleaching. The coral starves without it. Some corals can survive if the temperature returns to normal quickly enough. The temperatures did not swiftly return to normal in 2023.
During the worst of it, Dr. Cory Krediet, an Eckerd College marine scientist working rescue operations at Mote Marine Lab, described the shift in terms that were difficult to read without pausing. “We went from healthy reefs to bleach reefs, dead reefs within 10 days,” he said. It was something he had never seen in person before, he continued. It’s noteworthy that a coral scientist who has worked in this ecosystem for a living described what he saw as unprecedented. Not frightening. Not worrisome. Unprecedented.
This is especially challenging because there are multiple causes of the damage. It has never done so. The majority of attention is focused on rising ocean temperatures, which is understandable. However, since 2014, stony coral tissue loss disease has also devastated the Florida Reef Tract. This rapidly spreading disease has spread throughout the reef in ways that scientists are still trying to fully understand. When you combine overfishing, pollution, boat groundings, misplaced anchors, and the gradual chemical shift of ocean acidification, you have a multi-layered collapse, with each stress exacerbating the others.
On their own, the economic stakes ought to demand greater urgency than they currently do. Southeast Florida’s coral reefs are estimated by NOAA to be worth about $8.5 billion, supporting over 70,000 jobs and bringing in billions of dollars in revenue and sales each year. The reef serves as a buffer for coastal communities by absorbing about 97% of the wave energy from hurricanes and storms. Losing it is more than an ecological phenomenon. It completely changes the coastline’s risk profile.
The Florida Keys National Marine Sanctuary’s seven major reef sites are the focus of a phased restoration project that NOAA and a group of partners have called Mission: Iconic Reefs. By employing disease-resistant and climate-resilient coral strains, eliminating invasive algae, and reintroducing species like long-spined sea urchins that prevent seaweed from overpowering the reef structure, the objective is to achieve a 25% average coral cover across those sites. It is meticulously planned, serious work.
In all honesty, it’s also a race against circumstances that continue to deteriorate more quickly than restoration can keep up.
The scientists involved feel that what they are doing now is both necessary and insufficient; it’s not quite despair, but rather a sense of gravity. Only one of the two things that the people standing in the water with coral fragments and planting tools can do is slow down global emissions and provide local intervention for the reef. It’s difficult to ignore the weight of that disparity as you watch this endeavor take shape.
In reality, bleached coral appears white. Whole, frighteningly white. Not white. Not diminished. White as bone is white. It is also challenging to think of the Florida Keys in the same straightforward manner that most people do when they plan a snorkeling trip or peruse a travel magazine after seeing that picture from North Dry Rocks Reef—fire coral and staghorn, July 2023. There was the reef. Ten days later, it wasn’t.
