OFF THE COAST OF GALVESTON, Texas — Divers descending into azure waters far off the coast of Texas plunge below a horizon dotted with oil and gas platforms into an otherworldly landscape of seamounts covered in yellow, orange and pink coral as far as the eye can see.
Some of the healthiest coral reefs in the world are found in the Gulf of Mexico, about 100 miles off the coast of Texas. Sheltered in a deep, cool habitat far from shore, the reefs of the Flower Garden Banks National Marine Sanctuary offer a stunning amount of coral cover. But scientists say that like all reefs, they are vulnerable and their location will only provide protection for a limited time in the face of a warming climate.
“It’s really beautiful to see so much coral in one place; an experience that most people don’t get to experience on reefs today,” said Michelle Johnston, acting superintendent and research coordinator for the federally protected area.
The reserve experienced some moderate bleaching this year, but nothing like the devastation that hit other reefs during the record summer heat. Still, Johnston said this is one of her biggest concerns for the future of the shelter. Water that gets too warm causes corals to expel their colorful algae and turn white. They can survive when temperatures drop, but they are more vulnerable to disease and may eventually die.
Florida’s coral reef – the third largest in the world – experienced unprecedented and potentially deadly levels of bleaching over the summer. Derek Manzello, coordinator of the National Oceanic and Atmospheric Administration’s Coral Reef Watch, said at least 35 countries and territories in five oceans and seas have experienced mass coral bleaching so far this year. He said it’s too early to know how many of Florida’s reefs will recover, as coral can die as long as a year or two after bleaching.
Manzello said climate models suggest that all the world’s coral will experience severe bleaching every year from about 2040.
“If you have severe bleaching events every year, the prognosis is not good because that essentially means the corals don’t get a chance to recover,” he said.
Reserve officials say that even in the occasional years when Flower Garden Banks has experienced more severe bleaching than this year, it has recovered quickly due to its overall health and depth, and is already recovering this year.
A report expected in the coming months will look at the reserve’s vulnerability to the expected impacts of climate change.
The Flower Garden Banks is notable for the amount of coral cover — more than 50 percent on average in some parts of the reserve — compared to about 10 percent coverage in the Caribbean and Northwest Atlantic regions, Manzello said. The corals are also located about 60 feet below the surface and are surrounded by even deeper waters, compared to many reefs where corals are found just offshore in shallower water.
In the early 20th century, fishermen reported looking into the waters of the Gulf and seeing a colorful display that reminded them of a blooming garden, but it was such an unusual place so far from shore that scientists who who made the first dives in the 1960s, were surprised to actually find thriving coral reefs.
The corals in the Flower Garden Banks were able to flourish so far from shore thanks to mountainous formations called salt domes, which lifted the corals high enough to catch the light, Johnston said.
Divers travel from all over the world to see the reefs at Flower Garden Banks, where colorful fish, manta rays, sharks and sea turtles float through and worms that resemble Christmas trees pop in and out of corals.
Andy Lewis, a Houston attorney, said he knew from his first trip to the shelter about a decade ago that it “should be part of my life.” Lewis became a divemaster and is now president of Texas Caribbean Charters, which takes about 1,000 people on diving trips every year, about half of whom return.
“It’s just a real adventure,” said Lewis, who is also a member of the shelter’s advisory board. “I love getting on the boat.”
That boat leaves from a spot near Galveston, where the current of the Mississippi River drops sediment that turns the water near shore a murky brown. By the time the boat leaves for the shrine, the water is clear and blue.
“You fall down and you’re on top of living coral as far as you can see,” Lewis said.
Lauren Tinnes, a nurse from Colorado, described how during her dive this fall, she rounded a cliff and found herself surrounded by enormous reefs as schools of fish darted through. She thought the description from so long ago was appropriate: “It’s like a field of flowers,” she said.
The Flower Garden Banks is one of 15 National Marine Sanctuaries and two National Marine Monuments protected by NOAA’s Office of National Marine Sanctuaries, and the only one in the Gulf of Mexico.
The sanctuary consists of seventeen separate banks covering an area of 414 square kilometers. When it was designated in 1992, the shrine had two pews. The largest and most recent expansion of 14 banks took place in 2021, a process that included input from the advisory committee, which includes representatives from industries dependent on the Gulf, from oil and gas to recreation and fishing.
Johnston said one way to keep the reefs healthy is to reduce stress. That includes mooring buoys giving boats a place to dock so their anchors don’t damage reefs, and removing invasive species that can cause fish numbers to decline.
Manzello said such efforts are being made in the hope that greenhouse gas emissions will also be reduced globally.
“We need all these things happening together to really protect the coral reefs for the next 20, 30, 40 years,” Manzello says.
Coral reefs support approximately one-fourth of all marine species at some point in their life cycle. They are also economic engines. By providing fish with a home that keeps them healthy, they support commercial fishing and generate income from tourism.
“As coral reefs around the world are declining, we want to keep them that way when we find healthy ones,” said Kelly Drinnen, education and outreach specialist for the Flower Garden Banks. “And they serve as a kind of repository for what could potentially help another reef recover in the future.”
In fact, samples of healthy corals from the sanctuary are stored and studied in a laboratory at the Moody Gardens on Galveston Island, a tourist destination with an aquarium. This also includes growing coral fragments with the hope of one day being able to replant them.
The Flower Garden Banks were not damaged by the massive oil spill that followed the deadly Deepwater Horizon oil rig explosion in 2010, but other reefs in the Gulf were. Data collected from studying the reserve’s deeper habitat is used to help guide the recovery of those reefs.
Researchers are also studying the genetics of the Flower Garden Banks coral, including whether it is different from the species in Florida.
“The more knowledge we have, the better equipped we are to protect that reef,” said Brooke Zurita, senior biologist at Moody Gardens.
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Stengle reported from Dallas. LaFleur reported from Galveston.
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