What Lies Beneath
story by ASHLEY WETHEY, LDWF Public Information
BRETT FALTERMAN, LDWF Fisheries
Known more for its vast coastal marshes and productive fisheries than recreational diving, the Sportsman’s Paradise offers some unique diving opportunities for the brave-hearted who are willing to explore the inshore and offshore waters of the Louisiana coast.
Different reef types exist within the Gulf of Mexico, both natural and man-made. Because the shape and sediments of the Louisiana coast have been largely driven by the influence of the Mississippi River, natural nearshore habitats are not always ideal dive sites because of both current and low visibility. However, the advent of the offshore oil and gas industry provided new habitat for both fishes and divers to explore.
The expansion of Louisiana-based offshore diving was linked in time and place with many of the early dive clubs following the construction of offshore rigs.
Much of the early diving focused on spearfishing, with competitive spearfishing competitions hosted in Louisiana as early as 1959 in Grand Isle. The 1959 Grand Isle International Scuba Diving Tournament featured prizes for a King and Queen Spearfisherman, including an Austin Healy Sprite Sports car as a grand prize. The Louisiana Council of Underwater Diver Clubs (LDUDC) still organizes statewide spearfishing competitions, listing records on their site all the way back to the 1959 contest and currently lists 14 different participating clubs.
During the early years of Louisiana diving, several familiar historical faces emerged, including the French explorer Jacques Cousteau, who visited the area during the build of his R/V Calypso, which was constructed locally. Cousteau, who was known for revealing the mysteries of the deep to people for decades, visited with local divers at one of the earliest dive shops in the area, Tementos on the Westbank.
That spirit of exploration still draws divers in Louisiana, with opportunities for free and SCUBA divers both inshore and offshore.
ARTIFICIAL STRUCTURES KEY TO DIVE OPPORTUNITIES OFF LOUISIANA’S COAST
In the context of Louisiana’s coast, artificial structures fall into two main types: standing petroleum platforms and artificial reefs. Interestingly, the numbers of each are dynamic and inversely related.
The Bureau of Ocean Energy Management manages offshore lease blocks. BOEM leases areas and permits operators. They also set standards for what happens once a rig is no longer in operation. According to their database, there are currently 2,063 oil platforms in the Gulf of Mexico, which is actually a marked decrease from roughly 4,000 structures just 20 years ago.
Nearshore rigs are removed as they become less productive, with many of the larger companies focusing further offshore in deep water or in other parts of the globe. This creates an opportunity for our department’s artificial reef program, with the development of “Rigs to Reefs” in 1986. ‘Rigs to Reefs’ takes advantage of these structures to enhance fishing and diving opportunities. Since its inception, 393 structures have been added to the artificial reef program.
Louisiana lays claim to the world’s largest artificial reef created from the Freeport sulfur mine off Grand Isle. The sulfur mine, also known as ‘Grand Isle 9’ because of the oil lease block in which it is located, has over 1.5 miles of bridgework and is composed of more than 29 structures. The reef is in roughly 42 to 50 feet of water and has 27 feet of clearance. For safety of navigation, it is marked by five lighted buoys.
Inshore Artificial Reefs
In addition to the offshore ‘Rigs to Reefs,’ the department also has an inshore component that seeks to enhance recreational opportunities within Louisiana estuaries. This program currently includes 29 inshore artificial reefs, some of which are suitable for diving.
Underwater visibility is reduced and seasonally variable at the inshore sites, though Inshore Artificial Reef Coordinator Ashley Ferguson suggests the East St. Tammany Reef in Lake Pontchartrain as a potential inshore dive site. “The visibility at this reef is usually best in the fall (September through November), with visibilities sometimes ranging from 5 to 10 feet,” said Ferguson. “Sheepshead, speckled trout, redfish, and jack crevalle can all be encountered at this site in the fall, which contains 160 reef balls.”
SCIENTIFIC DIVING FOR DATA
Many wonder what attracts fish to these structures. Basically speaking, two factors: shelter and food. The food chain begins with the formation of barnacles and other encrusting organisms on these structures below the waterline. This sets the stage for small fish seeking shelter and food that the steel legs provide. Also, added to this food chain is food disposal thrown overboard by the rig personnel. These combined factors draw the smaller fish that larger fish feed on. In essence, the rig structure serves as a big oceanic chumming machine. Of course the final links in the chain are the commercial and sport anglers who are drawn to these reaping grounds to gather the bounty found therein. As such, diving is an integral component of many of the department’s aquatic studies, with surveys conducted both inshore and offshore.
The Gulf estuaries are home to reef complexes, primarily oyster reefs, which provide nursery habitat for fish and other wildlife, protection from predators, water filtration, and reduced erosion. During the month of July, SCUBA certified LDWF biologists dive onto public oyster reefs to estimate density and overall health of the oyster resource in Louisiana.
The gear used is a square meter frame, and it allows biologists to assess oyster populations to provide data on oyster recruitment, fouling organism density, recent oyster mortality and the presence of predators. The primary goal is to provide an annual estimate of available oyster resources from the public oysters seed grounds. Divers randomly place the one square-meter aluminum frame onto the previously marked and polled oyster reef. Then, certified SCUBA divers descend to the bottom and collect all oysters, shell, loose surface material and associated macroscopic organisms to a depth of approximately 6 inches within the frame. The contents are emptied into a marked receptacle, and the process is repeated five times in each reef. The numbers of oysters collected per square meter are multiplied by the estimates of reef acreage to produce an estimate of available oyster resources on public reefs in each basin across the state.
OFFSHORE DIVE SURVEYS
LDWF biologists based at our Grand Isle Fisheries Research Lab also use underwater surveys to monitor fishes associated with offshore structure. Beginning in May of 2011, department divers began to quantify fish assemblages and encrusting organisms at select platforms about 30 miles offshore from the GI Lab. Rigs were sampled in 15-foot increments from the surface to 120-foot depth, with surveys assessing both the inner and outer structure during multiple years and seasons. Lab Dive Safety Officer Charles Alexander reports, “We documented 84 different species during the initial series of surveys and are now using the same dive survey techniques to assess artificial reef and standing platform habitats statewide.”
FLOWER GARDEN BANKS NATIONAL MARINE SANCTUARY
Natural bank habitat also exists off the Louisiana coast along the shelf edge and represents a very unique and ‘diveable’ habitat type. Perhaps the most celebrated Louisiana offshore diving location is the Flower Garden Banks, a National Marine Sanctuary actually composed of two banks (the East and West Gardens) about 120 miles due south of extreme southwest Louisiana. Though distant from the coast, the coral-covered salt dome tops actually reach within 60 feet of the surface. While other shelf-edge banks exist, the Gardens are unique in that they are the only hard coral formations in the northern Gulf of Mexico. NOAA manages the preserve and is working on a Flower Garden Banks expansion plan to try to protect additional unique shelf-edge banks habitat in the northern Gulf.
WHAT TYPE OF DIVING IS BEST FOR ME AND HOW DO I GET STARTED?
‘Free diving’ is breath-hold diving, where a diver’s time underwater is limited to the breath they take at the surface.
The acronym SCUBA stands for ‘self-container underwater breathing apparatus’ and refers to cylinders that hold air or specialized gas mixes to extend a diver’s time and depth underwater.
Courses on both are available at dive shops across the state and conducted by two professional diving organization, the Professional Association of Diving Instructors (PADI) and the National Association of Underwater Instructors (NAUI), with purchase or rental of SCUBA gear available locally and requiring certification by a professional dive instructor.
- SAFE SAILINGLDWF’s Boating Safety Program Reducing Incidents And
- PHOTO FINISHPictures Of Harvested Deer In Louisiana Help Convict
- REEF RELIEFConstructing And Adding Structure To Small Ponds Can
- DIVE LOUISIANAWhat Lies Beneath story by ASHLEY WETHEY, LDWF Public
- BUILDING UP THE BOTTOMOyster Harvesting Is Both A Give And Take Process