OCULINA EXPEDITION 2005
Characterizing a Deep Coral Ecosystem and Assessing the Effectiveness of the Oculina Experimental Closed Area

MISSION DISPATCH 8
October 19, 2005
OHAPC - Gulf Stream, off the east coast Florida

Student Question and Answer Part III - Questions about coral and life on the Oculina reef:

Question 1: Are corals edible? Is it illegal to take coral? (Asha)

Answer 1: Corals are not edible, but some medicines, such as calcium supplements, are extracted from corals. Federal laws and regulations including the Magnuson-Stevens Fishery Conservation and Management Act, Presidential Executive Order #13089, and the Coral Reef Conservation Act were promulgated or re-authorized to protect corals. In addition, the NMFS recently recommended listing two species of shallow water corals, elkhorn and staghorn corals, as threatened under the Endangered Species Act. It is illegal to "take" scleractinian corals (hard corals like O. varicosa). If you are a scientist conducting research on O. varicosa, a special scientific permit that allows you to take samples is necessary to obtain. (Jocelyn Karazsia, NOAA Fisheries)

Question 2: Why doesn't Oculina coral have pretty colors like the shallow coral reefs? (Natalie)

Answer 2: Oculina coral grow at depths of 200 to 350 ft along the Oculina Bank. At these depths, there is not enough light reaching the Oculina reef to allow the symbiotic algae, zooxanthellae, to grow. Zooxanthellae are responsible for the pretty colors seen in shallow water coral reefs. In the absence of zooxanthellae, one can only see the skeleton of the coral, and in this case, the skeleton of O. varicosa is pure white. (Sarah Heberling, UM)

Question 3: Is Oculina coral soft when it is in the water and then hard when it is taken out? (Luis)

Answer 3: No, Oculina is a hard coral called a "scleractinian" coral. However, we also see a lot of black corals (antipatharians) within the OHAPC. Black corals have a hard skeleton but a softer appearance. Black corals are also called precious corals and are harvested in many parts of the world to make jewelry. (John Reed, HBOI)

Question 4: Is there a coral living in each hole of a coral skeleton or do the coral animals move around? (Patrick) Why do these holes look "hairy?" (Mariely)

Answer 4: Corals are colonial animals, and individual coral animals are called polyps. A coral polyp is very similar to a tiny sea anemone. Polyps are sessile (they cannot move around) and they extract calcium carbonate from the water to form a calcareous skeletal cup. The skeletal cup (or hole) provides protection for the polyp. Large numbers of these polyps grow together in colonies of delicately branched forms or rounded masses and give corals their "hairy-like" appearance. (John Reed, HBOI)

Question 5: Are corals dangerous to people? Can they bite or sting? (Nancy)

Answer 5: Some species of corals do sting. For example, when a snorkeler touches or rubs against fire coral it will sting. (Sarah Heberling, UM)

Question 6: What do corals eat? (Nancy)

Answer 6: The deep water coral, O. varicosa, eats zooplankton drifting through the water column. The zooplankton ride the Gulf Stream current and are carried up through the water column by upwelling events. The Gulf Stream carries the zooplankton from the nutrient-rich waters of the Caribbean Sea along the Florida coastline. Upwelling events bring zooplankton up from the bottom of the water column, within the reach of deep water corals. (Sarah Heberling, UM)

Question 7: Where does the name "Oculina" come from? (Keana)

Answer 7: The latin word for eye is "Ocu." When the scientist Lesuer first saw Oculina coral in 1820, he thought the coral polyps resembled little eyes, hence the name. (John Reed, HBOI)

Question 8: What is the temperature where Oculina coral grow? Does the temperature change much over time? (Jamie)

Answer 8: The temperature of the water in which Oculina coral grows changes seasonally. Researchers obtained an average temperature of 60 F from a temperature recorder placed on the sea floor (at a depth of about 270 ft) where Oculina grow. Temperatures ranged from a low of 45 F during cold water upwelling events to temperatures in the upper 70's during the warmer months of the year. (John Reed, HBOI)

Question 9: How old is the Oculina coral along the Bank? (Jamie)

Answer 9: Individual Oculina colonies grow at a rate of approximately a half an inch per year. Thus, large coral colonies (6 ft. tall) might be 100 to 200 years old! The reef structure itself has been radiocarbon dated, and structures that are 60 to 100 ft tall may be several thousands of years old! (John Reed, HBOI)

Question 10: When an Oculina coral mound is described as being "three stories high," what makes up that mound? What is it built upon? (Diane)

Answer 10: An Oculina coral mound is called a bioherm. The base of a large bioherm or tall reef is rock pavement, usually composed of limestone. The bioherm itself consists of coral debris (loose coral rubble) and sediment. A steel rod shoved into one such bioherm revealed that there exists at least 15 ft of loose coral rubble, debris, and sediment. Supporting this theory of bioherm construction and formation is core sample taken from a Lophelia coral reef in Sweden. Researchers discovered that the coral debris and rubble of the bioherms extended to approximately 450 ft.! (John Reed, HBOI)

Question 11: Do hurricanes affect Oculina coral? (Adrian)

Answer 11: Most deep water Oculina coral is below the main wave base of the ocean's surface. The wave base extends to about 50 m below the surface, which is above the depths at which Oculina grow. Thus, at the depths of the Oculina reefs, the effects of hurricanes, such as storm surge, are rather minor and do not affect the reefs. (Andy Shepard, NURC)

Question 12: If the Oculina reef is protected, will it grow closer to shore? (Ronesha)

Answer 12: Not necessarily, but hopefully more recruitment will occur, replenishing the inshore communities of Oculina. Oculina bioherms will not grow closer to shore because these large structures need the protection offered by deep water, below the wave base of the ocean's surface. (Andy Shepard, NURC)

Question 13: The sample of Oculina we looked at in class had marks on them that looked like fingers. Can you explain how coral samples are harvested? (Jasmine)

Answer 13: It is difficult to explain the "finger" marks you see on your sample of Oculina, without examining the sample, but the method of coral sampling can be explained. Samples of Oculina coral are obtained using either the Johnson-Sea-Link or Clelia submersibles, which have a manipulator arm attached. The manipulator arm, controlled by an operator inside the submersible, scoops up a sample of the coral and places it in a bucket. This bucket is then taken up to the surface and analyzed. (John Reed, HBOI)

Question 14: How many different kinds of animals live near Oculina coral? (Bryan)

Answer 14: One Oculina coral head the size of a soccer ball can support up to 2,000 marine organisms! (John Reed, HBOI)

Question 15: What is the most endangered animal you have found on the Oculina reef? (Santana)

Answer 15: Oculina varicosa is the most endangered animal found on the reef. Speaking in terms of fish, the larger groupers (e.g. speckled hind, snowy grouper, Warsaw grouper, and Goliath grouper) face the biggest threats. While some come back in population numbers for these species has been observed, it many take many decades for a full recovery, as these fish have very long maturation time of 5-10 years. (John Reed, HBOI)

Question 16: How big and how old can grouper grow? (Katherine) Where are the largest grouper? (Ronesha)

Answer 16: Goliath grouper are the largest of the grouper species, growing to a maximum size and weight of 6 ft, 500 lbs. The largest grouper are found at the base of the reef where rock reefs are or huge relief and well-intact Jeff's reed. Groupers like to hang out along hardbottom overhangs and ambush prey. (Stacey Harter, NMFS)

Question 17: What is the biggest grouper you ever saw? How do you measure it? (Javier)

Answer 17: Don't see big ones here any more. We use parallel lasers, mounted on the ROV. They are spaced 10 cm apart and the beam of light they project is aimed at a fish to determine size. The biggest ones seen now are 40-50 cm. Scamp is the most abundant grouper we see. (Stacey Harter, NMFS)

Question 18: How big are the grouper and how many of them are there when they hatch? (Karl)

Answer 18: When they spawn it is ususlly one male and a harem of females - typically they rush up in the water column and millions of eggs are fertilized. However, only a small percentage makes it to adult size. (Stacey Harter, NMFS)

Question 19: Do you ever see bull sharks, snakes, or other animals at the depths in which you conduct your research along the Oculina Bank? (Christopher)

Answer 19: We have seen more sharks on this expedition than any other recent OHAPC expedition. Most shark sightings occurred on the night ROV dives. (Stacey Harter, NMFS)

Question 20: Are the OHAPC and Experimental Closed Area closed for everyone or just commercial fishermen? (Philicia)

Answer 20: In 1984, the SAFMC recognized the special significance of the habitat and designated Oculina Bank as OHAPC. This action closed a 92-square-kilometer (300 square miles) area to trawling, dredging, longlining, and trapping. Additional restrictions apply to anchoring and possession of rock shrimp and Oculina while in this area. In 1994, the SAFMC created the Experimental Oculina Research Reserve, otherwise known as the Oculina Experimental Closed Area (OECA), which closed the area to all bottom fishing for 10 years. The OECA is located within the Oculina Bank OHAPC. All restrictions within the larger OHAPC apply. In addition, no person may fish for snapper-grouper species in the area or retain snapper-grouper in or from the area. The area was closed in order to evaluate the effectiveness of the reserve for the management and conservation of reef fish, namely the recovery of fish populations and grouper spawning aggregations. (Jocelyn Karazsia, NOAA Fisheries)

Question 21: Do the animals near the Oculina reefs have a longer or shorter lifespan than animals in other areas? (Alejando)

Answer 21: Grouper are generally have long lives and the Oculina coral itself has a long lifespan relative to other corals. In fact, Oculina can be several centuries in age. The Oculina reef habitat, much like a shallow water reef habitat, supports a diverse population of fish and invertebrates. Many of these fish live to be 10 to 20 years old, whereas invertebrates (e.g. shrimp and crabs) only live a maximum of 1 to 2 years. (John Reed, HBOI)

Question 22: Are fish born with bioluminescence or do they acquire it as they grow? (Ofelia)

Answer 22: Most fish found within the OHAPC are not bioluminescent. However, many deep sea fish do have this capability even at the larval and juvenile stages of their life history. (John Reed, HBOI)

Question 23: Have you found new species of plants or animals? (Matthew)

Answer 23: A number of new invertebrate species living within the Oculina coral have been discovered. New species of arthropods, sea spiders, brittle stars, and sea cucumbers were discovered during a study done nearly 20 years ago. Hundreds of invertebrates collected during this study have yet to be identified and of all the invertebrates collected, this just merely scratches the surface of what remains to be discovered! (John Reed, HBOI).

Question: 24: What is the most interesting thing you have found during this expedition? (Michael)

Answer 24: The black sea bass. This is an overfished species that has not been seen in many years. (Andy Shepard, NURC)

Watching the ROV video, seeing what organisms are living in each of the different types of habitats (e.g. sand bottom, areas of coral rubble and standing dead coral), is the most exciting part of these expeditions (John Reed, HBOI).

Question 25: Will the bacteria coming from Louisiana hurt the Oculina reefs? (Karl)

Answer 25: The bacteria coming from Louisiana will more likely affect the coral reefs of the Florida Keys than the Oculina reefs, however we do not know for sure what will happen. We do know that water from the Gulf of Mexico reaches the Oculina reefs, but we don't know how it will affect the reefs. The bacteria feed other organisms, that have the potential to smothering the coral. (Andy Shepard, UNCW)

Questions about ocean science:

Question 1: How big is the ocean and how much have you explored? (Acie)

Answer 1: The ocean covers 70% of the Earth's surface, yet humans know more about the surface of the moon than about the bottom of the ocean. Less than 1% of the sea floor has been mapped. The percentage of sea floor that has been mapped using multi-beam acoustic technologies and ground-truthed is much less than 1%. (Andy Shepard, UNCW)

Question 2: What kind of education is necessary to do this kind of work? (Rudy)

Answer 2: The formal education levels on the Liberty Star vary depending on the part of the research team in which you participate. Ideally, you need a mixture of operational experience, technical skills, terminal degrees, and advanced degrees to run a research program. (Andy Shepard, UNCW)







© 2005, Harbor Branch Oceanographic Institution