The northwestern Gulf of Mexico is scattered with topographic features in the form of underwater hills or mountains. These features, commonly referred to as banks, bring the ocean floor closer to the surface, providing suitable habitat for a wide array of reef and pelagic fish, algae and invertebrates. Together, they form a system of islands that support higher biological productivity than the surrounding ocean floor. These islands of productivity are connected to each other and to coastal and offshore ecosystems by virtue of the currents flowing through the Gulf of Mexico.

Many of the survey sites are rich palettes of color and texture created by the blend of fishes, sponges, algae, coral and other invertebrates. The level of light available at deeper depths has surprised researchers. This light source allows for the existence of many of these species.

This stunning leafy green algae (on the left) was documented during a recent submersible expedition by Ocean Explorer.

Erosive processes have carved a honeycomb network in the deeper areas of the banks. These formations are generally covered with colorful coralline algae, crinoids (a type of echinoderm, related to sea stars) and gorgonians (a type of coral). Species such as these creolefish (Paranthias furcifer) take advantage of the protective cover such areas provide.

Biological and physical processes have created a multitude of nooks and crannies that provide food and protection for a variety of fish and invertebrates.

At the Flower Garden Banks, the giant anemone (Condylactis gigantea) is found only in the deeper areas, not on the reef crest. In other areas of the Caribbean, this species is found in shallow areas. The reason for this difference is unknown.

Contributing authors:
Emma Hickerson, Research Coordinator
Flower Garden Banks National Marine Sanctuary

Shelley DuPuy
Flower Garden Banks National Marine Sanctuary

Ocean Explorer