Exploring Flower Garden Banks National Marine Sanctuary

By Guest Author Dive Locations Jul 14, 2016

For more than 40 years, national marine sanctuaries have worked to protect special places in America’s oceans and Great Lakes waters, from the Hawaiian Islands to the Florida Keys, from Lake Huron to American Samoa. Backed by one of the nation’s strongest pieces of ocean-conservation legislation, the National Marine Sanctuaries Act, the sanctuaries seek to preserve the extraordinary beauty, biodiversity, historical connections and economic productivity of our most precious underwater treasures. And — lucky for you — most of these places are accessible to recreational divers. Sanctuary waters are filled with unique ecosystems. They harbor a spectacular array of plants, animals and historical artifacts, all waiting to be explored. National marine sanctuaries belong to everyone, so dive in.

Cover image credit: G.P. Schmahl/NOAA

Flower Garden Banks National Marine Sanctuary

Within the vast expanse of open ocean known as the Gulf of Mexico, three vibrant coral reefs and sponge gardens burst with life. Venture 70 to 115 miles from the coasts of Texas and Louisiana and you’ll discover an exciting assortment of marine life. Gigantic whale sharks cruise overhead, and tiny brittle stars nestle into a coral reef that is thousands of years old.

Flower Garden Banks National Marine Sanctuary protects these northernmost coral reefs in the continental United States. It comprises three distinct reef systems: East and West Flower Garden Banks and Stetson Bank. These reefs rest atop ancient salt domes. Here, you’ll find more than 23 different species of coral serving as the foundation of complex yet balanced ecosystems.

Despite its distance from shore, marine debris still negatively affects Flower Garden Banks National Marine Sanctuary. As a diver, you can help this underwater ecosystem by removing marine debris, like this fishing line, when doing so will not negatively impact entangled organisms or pose a danger to yourself. Report entangled marine debris to your charter vessel captain or to Flower Garden Banks National Marine Sanctuary. (Photo credit: Emma Hickerson/NOAA)

Coral crests like this one are common throughout East and West Flower Garden Banks. Many formations have grown to be the size of cars. The larger the formations, the more nooks and crannies available for invertebrates like sponges and urchins to call home. (Photo credit: G.P. Schmahl/NOAA)

To see brain coral like this spawning in East Flower Garden Banks, divers must visit at night, usually between 7 pm and 10 pm. When diving at night, make sure you always carry at least two functioning dive lights at all times. This not only ensures your safety as a diver, but also the safety of the reef by preventing damaging collisions. (Photo credit: Emma Hickerson/NOAA)

With more than 300 species of fish found within sanctuary boundaries, coming face to face with a large grouper like this is not uncommon in such a vibrant and bustling ocean world. (Photo credit: G.P. Schmahl/NOAA)

Watch as Atlantic manta rays glide over the reef capturing plankton in their large mouths. (Photo credit: G.P. Schmahl/NOAA)

Each year, one of the most spectacular ocean events occurs within sanctuary boundaries. Seven to 10 days after the August full moon, these reef-building corals put on a fantastic spawning display when the reef explodes into a reproductive frenzy. Coral polyps release millions of gamete bundles (eggs and sperm) into the water column via broadcast spawning, creating what looks like an upside-down snowstorm. Gradually, the gametes float towards the surface. Here, they burst open to allow eggs and sperm from different colonies to combine, forming larvae that will eventually grow into new corals.

Recreational and scientific divers flock to this area to see these massive and ancient coral colonies exhibit one of the world’s most visually-prolific mass coral spawning events. To make the most of your visit, consult the coral spawning schedule developed by sanctuary scientists.

Flower Garden Banks National Marine Sanctuary is accessible only by boat. Visiting divers should find an experienced dive charter boat to make the journey offshore. If you choose to take a private vessel, make sure you’re aware of sanctuary boundaries and mooring buoy coordinates. By following proper reef etiquette, all divers can help protect this vital and vibrant marine treasure.

This species of coral, known as Orbicella faveolata or mountainous star coral, most commonly broadcast-spawns its gamete bundles on the eighth night after the August full moon, just after 10:00 pm. The eighth night is said to be the peak night of the Flower Garden Banks coral spawning event, when it really looks like you’re in an underwater snowstorm. (Photo credit: G.P. Schmahl/NOAA)

While many of the Flower Garden Banks National Marine Sanctuary corals are healthy, climate change has caused some corals within the sanctuary, like this spiny flower coral (Mussa angulosa), to bleach. Corals bleach when water temperatures are too high, causing coral to eject the colorful symbiotic algae they need to survive. (Photo credit: Joyce & Frank Burek)

A close-up image of this great star coral, or Montastraea cavernosa, shows individual coral polyps releasing sperm. Scientists have determined that these mass spawning events allow for genetic mixing and species dispersal over large distances. Despite some predation, the immense number of gametes released ensures survival of a significant number of coral larvae. (Photo credit: G.P. Schmahl/NOAA)

Divers can spot whale sharks in Flower Garden Banks National Marine Sanctuary during the summer months, particularly July, August and September, when the surface waters are calm and there’s plenty of plankton to go around. Perhaps while you’re here to witness the mass coral-spawning events, you’ll also get the chance to swim near the world’s largest fish. (Photo credit: Ryan Eckert/NOAA)

Non-native lionfish have invaded underwater habitats throughout the waters of the southeastern United States, Gulf of Mexico and Caribbean. Flower Garden Banks is no exception. While ornately beautiful, these fish have no natural predators in this part of the world and a voracious appetite. They pose a serious threat to other fish species and coral-reef ecosystem health. (Photo credit: G.P. Schmahl/NOAA)

Drop down at least 55 feet beneath the surface and you’ll be immersed in the beauty and tranquility of this coral-reef ecosystem. The abundance of life is obvious here as schools of fish dart above a myriad of sponges, corals and invertebrates at Stetson Bank. (Photo credit: Michelle Johnston/NOAA)

More than three decades of scientific reports call for more protection of this unique area. Thusly, NOAA has recently proposed expanding the Flower Garden Banks boundaries. The expansion could add an additional 15 banks located off of the Texas and Louisiana coasts. This expansion would grow the sanctuary to more than 380 square miles. Extending protection to these additional locations will limit impacts from bottom-disturbing activities and safeguard vital habitats. The public can comment on the proposed expansion online until August 19, 2016.

Experience the wonders of Flower Garden Banks National Marine Sanctuary and other national marine sanctuaries at sanctuaries.noaa.gov/earthisblue.