OCULINA EXPEDITION 2005
Characterizing a Deep Coral Ecosystem and Assessing the Effectiveness of the Oculina Experimental Closed Area
MISSION DISPATCH 4
October 15, 2005
OHAPC - Gulf Stream, off the east coast Florida
Fishery Resources of the Oculina Bank
The Phantom S2 ROV descended below the ocean surface three times today. In addition to the cobia, scamp groupers, barracuda, porgies, and bigeyes observed over the past two days, scientists experienced a spectacular sight during today's first dive - several juvenile black sea bass. According to senior scientist John Reed, adult black sea bass were once the most abundant fish on the Oculina reefs. However, habitat destruction and overfishing all but eliminated these important fish from the Oculina reef. In fact, Reed and others have not seen a black sea bass on the reef since 2000. Having the ability to study this area via ROV enabled scientists to have this significant breakthrough today.
As the ROV pilot, Lance Horn (NURC) assumes one of the most challenging tasks on the Oculina Expedition. However, few ROV pilots are as experienced as Horn, who has been SCUBA diving since 1976 and piloting ROV's since 1987. Horn has conducted over 1300 dives with the Phantom S2!
In addition to dealing with strong and variable currents and high seas, Horn has to position the ROV close enough the reef so that it can be studied, while keeping a safe distance away from the reef to prevent damage to these unique deep water coral resources and the equipment - the Phantom S2 ROV system and all of its peripheral equipment costs approximately $250,000! Through radio, Horn is in constant communication with the Captain of the Liberty Star and the rear ROV tender. This communication is essential to ensuring a safe and successful dive.
Having reliable and safe technologies to study the Oculina reef and associated fishery resources is critical. The Phantom S2 has proved to be an excellent tool for gathering more information on the OHAPC. This ROV is especially effective because it has two cameras mounted on its frame. One camera is a video camera that allows the ROV pilot to navigate. The video output of the camera includes a compass indicating the current heading of the ROV; the time in hours, minutes, and seconds; the date; and, the depth of the ROV. Additionally, the video allows the scientists to observe the fish of the Oculina Bank. The scientists record video images on both DVD and videotape for later reference.
The other camera mounted on the frame of the ROV is a digital still camera. In addition, two lasers and a strobe flash are mounted on the ROV. The flash illuminates objects within the view of the still camera and the lasers give a reference for distance, as they are mounted 10 cm apart from each other. The still camera is connected to a laptop in the laboratory through the ROV tether. In the lab, one the scientists manually takes a photograph of the sea floor along ROV transect every 60 seconds. These photos are archived on CD-ROMs.
Application to Science and Management:
Cobia (Rachycentron canadum)
This species is related closely to remoras and jacks. They are found throughout the world in warm coastal and ocean waters. Typically, they grow to an average size of about 6 ft. and an average weight of about 30 lbs. As adults, they are encountered frequently individually and in small groups, but are found rarely in schools. Cobia are migratory pelagics and likely utilize the Oculina Bank for foraging as they move up and down the Atlantic seaboard.
Scamp grouper (Mycteroperca phenax)
This medium-sized (approximately 2 ft max), long-lived fish is part of the Serranidae family and the snapper-grouper complex. During its life cycle, smaller individuals first function as females, then transform into males with growth. Scamp are important keystone species in the OHAPC and are also found along the continental shelf from North Carolina to Venezuela.
Black Sea Bass (Centropristis striata)
Black sea bass is also part of the Serranidae family and snapper-grouper complex. Like scamp, black sea bass can also change sexes during their life cycle. It grows to an average length of 2 ft. and an average weight of 8 lbs. Preferred habitat for black sea bass includes rocky bottom - where Oculina coral likes to grow!
Protecting these fish populations from further decreases in size and abundance is one of the primary goals of the regulations promulgated to effectively manage the OHAPC. Through protection of the deep water Oculina coral habitat, these fish have a safe haven available for breeding, maturing, and feeding. We can't help but wonder if the sighting of black sea bass today is an indicator that the OHAPC and habitat protection measures are functioning as designed.
TEACHER RESOURCE - Dive Data [ Excel Spreadsheet ]