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Feature

Underwater Theater

For divers off Texas coast, curtain opens on cast of extraordinary coral-reef creatures

A blue and yellow fish the size of my index finger darts across the dimpled surface of a pale green coral sphere. A school of brown chromis, four inches long with fins that seem to have been dipped in yellow, circle us, and a French angelfish the diameter of a dinner plate cruises past. My scuba diving buddy Jacqueline Stanley points at what appears to be a black marble with yellow spots hovering above the coral. I look closer and discern a tiny snout and tail; the swimming marble is a juvenile smooth trunkfish, one of the smallest denizens of the coral reef, and not easy to find. We give each other an underwater high-five and fin away to gawk at dozens of other creatures that inhabit this thriving coral reef.

While it might sound like we’re deep in the Caribbean, Stanley and I are actually 100 miles off the Texas coast. Here, a piece of beneath-the-surface tropical paradise called the Flower Garden Banks National Marine Sanctuary flourishes where salt domes on the floor of the Gulf of Mexico rise close enough to the surface to support coral reefs. These reefs probably originated more than 10,000 years ago when baby coral organisms, called polyps, floated on currents from reefs off Mexico’s Yucatán Peninsula, about 400 miles away.

The Texas Flower Gardens, as they were called, likely were discovered by fishermen in the late 1800s. As the story goes, they named the banks after the brightly colored sponges, plants and other marine life they sometimes snagged or could see on the colorful reefs below from their boats.

Later, divers found the reefs enthralling, and in 1979, the Houston Underwater Club submitted a formal nomination for the creation of a National Marine Sanctuary protected under federal law. That official designation finally came in 1992, with two sites—the East Flower Garden and West Flower Garden banks—forming Flower Garden Banks, the first such sanctuary in the Gulf of Mexico.

A third site, the Stetson Bank, was added in 1996. The three sections protect about 56 square miles of critical marine habitat, with roughly 1 percent of it shallow enough for coral—and recreational divers.

Blue, Clear Water

The only way to reach the Flower Gardens is by boat, and we came here aboard the Fling, a dive charter based in Freeport. We left the dock late in the evening, sleeping in berths below decks as we traveled to the sanctuary. The crew roused us at 7:30 the next morning for our first dive, at the West bank.

On the back deck, scuba tanks line the sides, wetsuits hang overhead and gear is stashed everywhere. I haven’t had my morning coffee, instead relying on excitement about the coming dive to get me going. One of the first things I notice is the water, a travel-brochure-worthy blue, and incredibly clear. I gear up, step off the side and descend. I look up and can see the shadow of the boat bobbing on the surface 70 feet above; and in the distance, the shadowy shapes of schools of large fish. Outstanding visibility, or “viz” in scuba parlance, is one of the Flower Garden’s signature traits.

The sheer volume and variety of life here is another. Stanley, an educator and artist in Houston, has been diving around the world for almost 40 years, yet was impressed by the wealth of healthy corals and fish when she first saw the Flower Gardens four years ago. More than 20 species of hard coral grow here, with their wild variety of colors, shapes and combinations making every dive a different experience. The sanctuary is also home to at least 280 species of fish, and despite poring over my reef fish identification book before and after every dive, I don’t come close to naming everything I see on our nine dives on the 2 1/2-day excursion.

In fact, the sanctuary contains the healthiest reef habitat in North America, according to Quenton Dokken, executive director of the Gulf of Mexico Foundation, a conservation organization focused on the Gulf and Caribbean Sea. That’s especially meaningful given that coral reefs represent one of the most endangered ecosystems on the planet. At many of the world’s reefs, intense fishing pressure is reducing the numbers of fish species that are necessary for maintaining a healthy reef. For example, many reef fish eat algae, and without enough of them keeping it at bay, this marine plant can grow so thick it actually smothers corals.

This isn’t a problem for the Flower Gardens, mainly because the sanctuary lies 100 miles from shore, which keeps the fishing pressure down. At least so far.

Manta Ray, But No Whale Shark

After two morning dives at the West bank, we head to High Island 389A, an offshore oil platform inside sanctuary boundaries. As a matter of fact, the Flower Gardens sit smack in the middle of one of the world’s busiest oil and gas production fields. While spills and accidents pose a potential threat, Dokken points out that, as yet, no incidents have harmed the reefs. In fact, as he sees it, the health of the sanctuary proves that oil and gas production and a healthy marine environment can co-exist, provided the industry takes to heart the challenges of operating in a sensitive area.

Offshore structures actually make excellent dive sites, supporting coral and sponge communities and attracting schools of fish and other marine life seeking shelter from the surrounding open water.

Beneath High Island, I watch a sea turtle nibble at tiny sponges growing on the enormous legs of the structure, while a large school of shiny jacks weaves among the supports. I swim in close and follow a bar that runs between two legs of the platform, amazed at the abundant and colorful miniscule creatures growing on it.

Next morning, we dive twice on the East bank. Here, I notice patches of white on an enormous brain coral, a rounded, boulder-sized ball of ridged coral that, true to its name, resembles a human brain.

Reefs are made up of thousands of individual coral organisms living inside a calcium skeleton. These organisms feed by sticking out tentacles to collect microscopic food, but get most of their nutrition from special algae that cohabitate with them. Actually tiny plants, algae use photosynthesis to convert sunlight into food. Corals sometimes expel these algae when stressed, such as when water temperatures rise higher than normal. Scientists call the resulting effect “bleaching” because the loss of the algae deprives coral of its color, leaving it looking white. Without the algae to provide oxygen and help feed them, coral organisms can die.

In 2005, coral reefs all over the world suffered from bleaching, with up to 45 percent of coral at the Flower Gardens affected, according to Emma Hickerson, the sanctuary’s research coordinator. Worldwide bleaching occurred again in 2010, affecting some 7 percent of corals at the Flower Gardens.

On subsequent dives, I find myself looking for telltale white patches, and I almost always discover at least a few small ones. Fortunately, Hickerson also says that many corals recover from bleaching once water temperatures return to normal.

On our second East bank dive, I spot a manta ray, its wide, winged body—at least 12 feet across—soaring past like some kind of underwater spaceship. Mantas have unique spot patterns on their undersides, and sanctuary staff members have collected photographs of those seen here into a catalog of more than 75 identified individuals.

I didn’t bring an underwater camera, but several other divers on the boat snap photos of the manta, which we compare against the database on laptop computers back on the boat. In summer, divers sometimes spot whale sharks around the sanctuary. These enormous sharks can grow to 50 feet long and weigh 10 tons, but they have only tiny teeth and eat plankton. Scientists aren’t sure what attracts the gentle giants here.

I spend the entire trip hoping for a glimpse of one with no luck, only to hear that several weeks later, a 20-foot male made an appearance.

Another sighting a few weeks after my visit was decidedly less welcome. Divers photographed a lionfish—a brightly striped, foot-long fish with venomous spines—that’s native to the Indo-Pacific and has spread along the East Coast as far north as Rhode Island and as far south as South America. They are voracious eaters; research has shown that one large lionfish is capable of reducing the number of other fishes in an area by almost 80 percent in just five weeks—perhaps because native fish simply don’t recognize these recent arrivals as a threat and swim right up to them to become lunch.

While lionfish encounter natural predators in their native habitat, they have few known natural predators in the Atlantic or Gulf. Invasive species like lionfish can upset the balance in a coral reef ecosystem, and their arrival has the sanctuary staff worried.

Hope for the Future

We dive another platform before the boat chugs to the Stetson bank while we sleep. Located about 30 miles northwest of the East and West banks, its slightly cooler waters support fire coral. Its bright yellow branches rise from the seafloor like a mustard-coated miniature forest, along with a variety of colorful sponges, including barrel sponges, which resemble flower vases. I peer into a few of them and occasionally spot a tiny fish or crab hiding out.

There are plentiful schools of large fish such as jack, mackerel and spotted eagle rays and an assortment of reef fish of all sizes. I’m thrilled to spot a sailfin blenny, a baby carrot-sized fish that rises up from a hole in the sand to wave an undulating fin along its tiny back. What it lacks in size, it makes up for in chutzpah, seeming certain that this display will scare off any unwelcome guests.

As Stanley and I return to the surface at the end of our last dive, the colors of the reef fade to blue. We pass another school of shiny, silvery jacks and a couple of torpedo-shaped barracuda, which move closer, curious. I think back to the first day’s sighting of the tiny juvenile trunkfish. It seems an apt symbol of hope for the future of these reefs.

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Melissa Gaskill, frequent contributor