Developing Culture Techniques to Conserve Coral Reefs in the Florida Keys

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1 Developing Culture Techniques to Conserve Coral Reefs in the Florida Keys March 2006 Progress Report Submitted to Steve Martin Ocean Reef Rod and Gun Club Principal Investigators Dr. Kevan L. Main, Dr. Kenneth M. Leber & Dr. David Vaughan Mote Marine Laboratory March 27, 2006 Mote Technical Report # 1087

2 Overview on the ORRGC Coral Culture Project: In August 2004 and March 2005, Mote Marine Laboratory (MML) received grant awards from the Ocean Reef Rod and Gun Club (ORRGC) to develop the culture technology to produce several species of hard corals for reef restoration research. We have made substantial progress in developing culture methods for the corals found in the Florida Keys over the past two years. The coral culture for reef restoration program is a collaborative research effort between the Florida Keys National Marine Sanctuary (FKMNS), EarthEcho International, and three of MML's research centers: Center for Aquaculture Research and Development Center for Fisheries Enhancement Center for Coral Reef Research The support provided by ORRGC in 2004 provided critical bridge funding to MML's Center for Aquaculture Research and Development to purchase culture system equipment and culture supplies required to continue the coral aquaculture work at the Tropical Research Laboratory (TRL) in Summerland Key. The 2005 ORRGC funds provided partial salary support for David Lackland (coral culture specialist at TRL), culture supplies for the coral culture research and funding to support the design and construction of the new quarantine system. The 2005 award was instrumental in our ability to obtain matching support for coral aquaculture through the FKNMS in 2005 and the Florida Coral Reef License Plate Program in This progress report will update the ORRGC on the exciting progress our program over the past year. We shifted the focus of the planned construction efforts in 2005 because of a critical need to build a quarantine system for introduction of rescued coral colonies from field sites. This year's efforts resulted in the design, construction of the new quarantine system, as well as continued work to develop culture techniques for 23 coral species found in the Florida Keys. Growth of coral colonies was documented and we continued to have success in fragmenting and producing new colonies for the environmentally controlled culture lab at TRL. In 2006, we would like ORRGC to consider a request to continue supporting Mote's Coral Aquaculture Research. The coral culture program will be expanding systems in the environmentally controlled culture lab, which will provide expanded growing space for coral species. The ORRGC funds will enable us to construct the systems to produce colonies for reef restoration research with several key coral species. We respectfully request level funding ($10,000) from ORRGC in 2006.

3 2005 ORRGC Progress Report: Mote's new coral quarantine system is making waves Culturing coral fragments that are rescued after a boat grounding event is a fragile, tenuous endeavor. With each new "patient" introduced to the hospital comes the realistic threat of a harmful pathogen or disease being introduced as well. MML's previous quarantine procedure consisted of fragmenting clones from parent colonies, a series of osmotic dips in fresh water, and direct placement of rescued corals in our environmentally-controlled coral culture laboratory at Summerland Key (Figure 1). Figure 1. Coral culture tanks at TRL' s environmentally controll~d laboratory. In some cases, corals that initially appeared to be healthy would begin to wane (color fading, loss of tissue or just not growing). We suspected there was an unidentified pathogen or biological agent (disease), which had found its way into the system through the introduction of new coral colonies (most likely hitching a ride internally). Since Mote's coral culture effort's focus mainly on rehabilitation followed by reintroduction to the natural environment being the next step in the procedure, the use of drugs or antibiotics was completely out of the question. Our solution was to create a separate quarantine system to "observe" newly acquired, and/or fragmented coral colonies for prolonged periods of time prior to placement in the coral culture laboratory. Although this approach was not expected to eliminate all pathogen issues, we believe this approach will provide a much greater safety net to protect our cultured coral species from disease.

4 Constructing the Quarantine System A 125-gallon glass aquarium was chosen because of its large size and observational benefits (Figure 2). All of the coral culture systems at TRL are equipped with artificial wave/current making devices (e.g., computer microprocessors, timers, and motion detectors), which trigger the corresponding wave pumps on and off. Because wave action was primary concern, we installed a device that mimics the large scale laminar wave surge found just above corals on the reef. A secondary or inadvertent" plus" to this type of application is the constant rising and lowering of the surface water level in the system. This change in water height creates an increase or decrease in light, similar to the changes that corals experience in natural systems. Figure 2. Quarantine tank: prior to construction of filtration and wave generating device. In most coral systems (from hobbyist to professional culture operations), the goal has been to create "stable systems". This simply means that the culturist tries to maintain water chemistry and physical parameters as constant as possible. The major advantage we have at Mote is location. We are located next to the Florida Keys coral reef, we have boats and gas, initiative, and staff to go out to the reef. Those staff can observe the corals and the"'environmental conditions that corals are exposed to. Our staff is out on the reef on a weekly basis. This frequent sampling has revealed that the water quality, conditions, temperature, light, and currents are not stable (there are high and low parameters both daily and seasonally. When interviewing Erich Bartels, Dive Operations Manager and the Keys staff member with the most logged dive times, if he had ever witnessed two similar days underwater, his response was an immediate "absolutely not!... in the seven years of diving in the Florida Keys I have never witnessed two days with exactly the same conditions".

5 Once the tank was purchased and set-up, we needed to drill openings in the tank to facilitate moving a large volume of water in and out of the system. These openings were made with diamond tipped hole saws and a lot of patience. Then we constructed the surge tank, which consisted of a single 50-gallon plastic tank on an elevated stand, two incoming water lines that enter the surge tank from the side (Figure 3). These water lines fill the tank. The bottom of the surge tank is fitted with two toilet flushing devices and the plungers are attached, with surgical tubing, to a single mooring buoy. As the tank fills, the buoy rises and VAVOOM, both plungers are activated simultaneously, allowing 50 gallons of water to pass through the side of the system every 65 seconds. Figure 3. Closeup of the surge tank that generates waves in coral culture system. The culture tank is equipped with drainage overflow pipe that is connected to a 90 gallon sump located on the ground just to the right of the culture tank. This 90 gallon sump houses all of the chemical (carbon) and mechanical (filter bags and protein skimmer) filtration elements. It also contained mangrove plants and a coral substrate to further support biological filtration. Another issue in the quarantine system design is the substrate. Most of the corals we are rehabilitating and/or culturing are found on top of the reef. There are two primary reasons for the success of these coral species: LlGHT- light provides energy for the symbiotic relationship between the zooxanthellae (algae living inside the coral tissues) and coral host WATER MOVMENT - moving water provides food, limits sedimentation, and facilitates respiratory requirements of these sessile invertebrates. Although some corals are adapted to live lower on the reef structure, it is believed that these corals can tolerate or perhaps even benefit from slight exposure to sedimentation. This same sedimentation exposure would kill a reef top species, such as Acropora palmata. In addition, the sand substrate would limit the amount of surge we could expose our animals to and we knew we needed to grow our corals with a lot of surge!

6 Figure 4. Sump and wave generating equipment. Blocks of coral skeleton, mined from Homestead, Florida, were already being used as a substrate in some of our culture tanks. This substrate note only worked well as a sediment free growing arena for growing corals, but it also provided added filtration to the culture tank. These coral skeleton blocks not only support nitrifying bacteria, but denitrifying and heterotrophic bacteria as we". These bacteria are all required to fulfi" the nutrient and filtration requirements in a marine system. A local artist donated the coral tiles and we cut the floor of the system with a tile saw, and put the coral tiles in place. Figure 5. Quarantine tank with coral substrate blocks installed.

7 Another filtration element we wanted to apply to the system was a "refugium" (a separate tank connected to the main culture system that would supply additional live food, or zooplankton, to the corals). This type of tank (Figure 6) creates a "refuge" (thus the name refugium) for small crustaceans (amphipods, copepods, shrimps, crabs, etc.) to live and reproduce without being completely consumed by the corals. Figure 6. Closeup of refugium tank: for small crustaceans and other zooplankton. As the crustaceans grow and reproduce, they are siphoned into the main quarantine tank by gravitational overflow and are consumed by corals and fish. The refugium consisted of three uniquely different prey organism tanks (Figure 7). Refugium Tank 1: Refugium Tank 2: Refugium Tank 3: a slow moving high-nutrient mangrove ecosystem a fast moving intertidal zone a combination of one and two Figure 7. Refugium tanks located above quarantine tank: system. Because the quarantine system is located indoors, artificial lighting was our only option. However, we wanted our new system to continue to reflect some of the change and variability encountered in nature. To mimic sunrise, sunset, and the intermittent passing of clouds we used a combination of stationary lights and timers (creating dusk to dawn)

8 accompanied by a moving light on a motorized track (creating the same effect as a "break" in cloud cover). Once the system was filled with water, tested and approved for use, it was time to introduce indigenous fish, live rock, and macroalgae to the culture tank and refugiums to stabilize the water chemistry. The type of rack system previously used in our environmentally controlled coral culture laboratory had to be modified to withstand the high wave energy within the system. We designed a shelf to support the mounted coral fragments, using the same coral-skeleton material we used for the base application (Figure 8). Figure 8. Coral support stand in quarantine tank: system. Later we added a few PVC coral supportbars, consistent with our other coral culture systems. These bars facilitate easy transfer of coral fragments from tank to tank. Once the system was complete, we ran the tank system for several weeks. The purpose was to stabilize water quality conditions prior to introduction of corals. Then the first "patients" from the dredging work being done at the Key West naval pier were added (Figure 9).

9 Figure 9. Addition of the first corals to the quarantine system. Since this new surge-quarantine system at TRL was set up, it has proven to be an amazingly stable and important screening tool for our Coral Culture Program. In 2006, we are going to construct four new raceway systems slated for our Environmentally Controlled Coral Culture room. The successes seen with this quarantine system design will be incorporated into the design of the raceway and future culture systems.