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OCULINA EXPEDITION 2005 Characterizing a Deep Coral Ecosystem and Assessing the Effectiveness of the Oculina Experimental Closed Area MISSION DISPATCH 7 October 18, 2005 OHAPC - Gulf Stream, off the east coast Florida Oculina Reefs And Change Over Time Science: Oculina varicosa is a slow-growing, delicate, and branchlike coral that is often associated with high biodiversity because thickets provide ideal spawning sites for numerous species of reef-dwelling fish, including economically significant fish like grouper (gag and scamp). Otherwise known as ivory tree coral, O. varicosa occurs in depths of several meters to greater than 100 meters. Contrary to the shallow depth colonies, which are relatively small with stout, club-like branches, deep water colonies may grow up to several meters in diameter and clustered in a thicket-like habitat. Based on average growth rates, some deep water Oculina reefs are thought to be at least 1526 years old! 
In depths of 50 m or greater O. varicosa typically grows on limestone
pinnacles. In addition, deep water Oculina lacks zooxanthellae, the
symbiotic algae that provide corals with their color and part of their
nutrition; therefore it is white at these depths and relies solely on free
swimming food. Oculina reefs typically occur in an upwelling region on the
shelf edge. Scientific studies have shown a very high diversity of
invertebrates, with thousands of species represented in the interstices of
the Oculina coral heads. Other studies showed that highly prized species of
grouper, gag and scamp, form large spawning aggregations in Oculina habitat
in February and March.
In the South Atlantic, Oculina reefs are distributed along the continental shelf with concentrations occurring off the east-central coast of Florida. Shelf-edge prominences, or limestone "pinnacles," lie near the 80 m depth contour off east-central Florida and extend tens of meters above the surrounding sea floor. This area, called the Oculina Bank, is located approximately 15 miles offshore Fort Pierce. The Oculina Bank has suffered extensive habitat damage due to mobile fishing gear (trawls and dredges) and anchoring activities. Structural damage ranges from toppled and broken coral heads to dead coral rubble, the individual pieces of which rarely exceed 2-3 cm in length. 
Scientist Profile: John Reed has been studying the deep water Oculina reefs
since 1976! Reed works in the Division of Biomedical Marine Research at
Harbor Branch Oceanographic Institution and is a co-Investigator in this
expedition. Reed has logged 35 deep water lockout dives with helium-oxygen
from Johnson-Sea-Link submersibles, primarily on the deep water Oculina
reefs. In addition, Reed has logged over 2,000 scientific scuba dives and
over 150 scientific dives in the Johnson-Sea-Link and Clelia submersibles.
Reed's research has resulted in over 40 publications and the establishment
of the 300 square nautical mile OHAPC.
No one other than Reed may be better able to evaluate the changes at the OHPAC over time... Changes in the Reef: During the mid-1970s to 1980s, the Oculina coral reefs thrived with live coral thickets. Over time, observations of the northern portions of the reef, especially off of Cape Canaveral, revealed that these same reefs, which once thrived, were reduced to rubble - like a steam roller had plowed over the reefs. This destruction could only have one probable cause - both legal and illegal trawling. 
In areas where 1-3 ft. tall standing dead coral thickets appear and no
obvious signs of human activity exist, the causes of coral death are less
certain. Around the world, shallow and deep water coral reefs are
experiencing the effects of changes in water temperature and of pathogens
and disease. How these factors affect deep water reefs has been poorly
studied and warrant further investigation.
Continued protection of the reefs with the existing boundaries of the OHAPC serves two purposes: (1) to protect the remaining thickets of live coral, which occur in areas of high bottom relief and in flat, sandy areas; and, (2) to protect the standing dead and coral rubble areas. By protecting both of these areas, it may be possible to see recruitment of coral larvae, causing an increase in the percentage of live coral cover over time. It will also be possible to continue investigating many of the unanswered questions we have about the effects of a changing environment on deep water corals. 
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