The Oculina reefs, in depths from250 to 300 feet, were built over the past thousand years or so by thedelicate ivory tree coral Oculina varicosa, and include a series ofspectacular pinnacles, mounds, and ridges that can grow up to100 feethigh. Deepwater Oculina reefs are not known to exist anywhere else onthe planet besides off Florida.
Fishing for shrimp and scallopshas damaged a large portion of the concentrated coral areas of thesereefs over the past three decades. However, the remaining healthy reefsstill support dense and diverse populations of more than 70 fishspecies and are critical breeding grounds for commercially importantpopulations of gag and scamp grouper as well as rock shrimp. The reefs'location directly under the Gulf Stream makes them a potentiallyimportant source of fish larvae for the entire southeast U.S.continental shelf.
Harbor Branch Oceanographic Institutionscientists first discovered the deepwater Oculina reefs with theJohnson-Sea-Link submersibles in 1975. John Reed, a Harbor Branch coralexpert and expedition co-principal investigator, nominated the Oculinareefs to for protection in 1981. In 1984, NOAA approved the the SouthAtlantic Fishery Management Council's (SAFMC) designation of 92 squaremiles of the Oculina reefs as a coral Habitat Area of ParticularConcern (HAPC) where the use of bottom trawling, longlines, fish trapsand anchoring by fishing vessels was prohibited. In 2000, the CoralHAPC was expanded to 300 square miles and now extends from Fort Pierceto Cape Canaveral. The original 92 square-mile area, now known as theOculina Experimental Closed Area, has further restrictions includingprohibition of bottom fishing for snapper and grouper species. However,surface trolling for species such as dolphin, tuna, and sailfish isstill allowed in the Experimental Closed Area and the larger HAPC sinceit poses no threat to the reefs.
"The [SAFMC] has led the nationin managing deepwater coral ecosystems by setting up this reserve, itis now up to scientists to show if it's working," says expeditionleader Andy Shepard from the National Oceanic and AtmosphericAdministration's Undersea Research Center (NURC) at the University ofNorth Carolina, Wilmington.
The Oculina expedition, funded byNOAA, will run from Oct. 12-18 on board the M/V Liberty Star, a NASAspace shuttle support ship operated by United Space Alliance andnormally used to retrieve spent solid rocket boosters. A second relatedexpedition is planned for May 2006. To explore the reefs, researcherswill be using NURC's Phantom SII Remotely Operated Vehicle (ROV), anundersea robot equipped with video and still cameras and a manipulatorarm for gathering samples. Team members will also be filing dailydispatches from the ship at www.at-sea.org.
One of theexpedition's goals is to "ground truth," or verify, a newly producedhigh-resolution multibeam sonar map of the region, which offersunprecedented resolution to reveal bottom features that were previouslyindistinguishable. The team will explore various areas using the ROV tocompare observations with what appears on the map. This will allowscientists to associate certain colors and other map features with thetype of habitat they indicate, such as sand bottom, coral ledges, orcoral rubble, allowing more accurate assessment of the extent of thereefs and likely identification of previously unknown coral features.
"Understandingthe extent of the reefs and where the most important habitats are willhelp researchers and managers determine those areas that need thegreatest protection, and those that might require less protection, "says Reed.
Another important focus of the expedition will be toassess populations of snappers and groupers and choose sections of thereef for initial monitoring surveys to be used as benchmarks. Throughcomparisons over time with repeat visits scientists will be able toassess progress in the Oculina Experimental Closed Area for restoringcoral cover and replenishing fish stocks. Recent expeditions havealready revealed encouraging signs that fish populations in thissection are slowly but surely increasing. In coming years, researchershope to see populations of snappers and groupers recovering enough toagain form large breeding aggregations in the area.
"We need toestablish a statistically and scientifically sound basis to assesswhether the habitat and fisheries are changing over time, and whetherthe reserve and enforcement are working," says Reed.
A final goalfor the cruise will be to collect samples of Oculina coral whosegenetics will be analyzed back on land and compared against that ofOculina found in shallow water, which is much more common. The purposewill be to determine if the deepwater version is a distinct species.This information is significant because the Washington, D.C.-basedadvocacy group Oceana has petitioned the federal government to includethe deepwater form of Oculina under the Endangered Species Act, whichwould only be possible if it is in fact a genetically distinct species.
Participatingin the expedition are scientists from the NOAA Undersea Research Centerat the University of North Carolina at Wilmington, Harbor BranchOceanographic Institution in Ft. Pierce, the NOAA Southeast FisheriesScience Center in Miami, the University of Oregon's Institute of MarineBiology in Charleston, the Florida Wildlife Research Institute in St.Petersburg, and the Vero Beach-based Estuarine, Coastal and OceanScience, Inc. (ECOS), and the University of North Carolina at ChapelHill.
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