Difference between revisions of "Team:Georgia State/Human Practices"

Kim Stone is a curator of fish and invertebrates at the GA Aquarium, which is less than a 20 minute walk from GSU. We had an incredible talk with her, and she walked us through some of the basics of coral husbandry. We may even partner with the GA aquarium in the future when we’re ready to test our modified algae in a closed coral reef system. From Kim Stone, we learned: No one knows if coral expel their algae or if the algae themselves leave the symbiotic relationship Factors regarding corals uptaking algae: Energy expenditure Is the energy wasted on uptaking algae worth it if the coral is already in a healthy symbiotic relationship? So, if the coral is healthy with our modified algae, the algae will most likely not be expelled for other, natural algae. The mother coral’s algal symbiont The mother passes on her symbiont to her offspring The offspring can also uptake algae from the environment. Coral Husbandry Protein skimmers are devices that remove organic compounds from the water. It balances nutrients, pH, and organic materials in the tank. A small number of storms can be good for corals because it changes the water, which can eliminate sedimentation/pollution buildup. Also, this allows for asexual fragmentation to occur, which can disperse corals around an environment. Fluorescence can be used as a measure of health High fluorescence= good health Coral Model Organism Large polyp indo-specific stony coral would work best. For example, Caulastrea. Hard/stony because it’s easy to see any signs of bleaching before the coral actually dies. A small coral is hard to observe and culture How to induce the coral to uptake our modified algae: Stress the corals enough to bleach them but not kill them. Do this by increasing the heat of system gradually by 2°F every other day until signs of bleaching (at about 84-86°F) Hold the temperature at 85°F for a couple of days unless signs of bleaching occur sooner In another tank, maintain the temperature at 85°F . Place the, now bleached, coral in. Gradually bring the temperature down to optimal levels. Add algae when the temperature reaches the algae’s optimal level. Have multiple tanks with various algal densities to determine the best concentration Monitor the attempted-modified coral polyps If there are new polyps, Verify if our algae are there. No one knows if this will work. Notes: Use 10-gallon tanks Certain artificial lights can harm the corals The tanks need water flow. If not, one must change the water every day Monitor pH, NH3, etc. using water test kits commonly found at fish stores Target feeding can decrease the amount of maintenance required. Aeration is essential. To eliminate any extra variables, use the same coral species and number/size of the colonies. Integrated Human Practices Detailed: Model Organism Initially, we were going to introduce our algae to one of the most common coral species in the Carribean: Elkhorn coral. After speaking with Dr. Joyner at GSU, she suggested that we use the sea anemone Aptasia as our model organism instead. Aptasia is easy to culture and uptakes algae during both its adult and larval life forms just like coral do. However, Kim Stone, a coral specialist, recommended Caulastraea furcata, which is a coral commonly found in the Indo-Pacific region. Corals found in this area are typically easier to obtain. Caulastraea is also a large stony coral. It’s easier to see early signs of bleaching in hard/stony corals compared to softer ones. Additionally, smaller corals are harder to observe and culture than larger ones are. Algae Diversity At the beginning of this project, we had a plan to introduce a single modification into a single algal species to incorporate into the coral-algae symbiosis. However, we learned from Alanna Waldman that a broader range of algal diversity typically leads to healthier, more bleaching-resistant corals. So, we changed our plan to include a variety of modifications into several different Symbiodinium. For example, we may introduce genes that encode for greater production of fluorescent proteins into one alga while we introduce genes for more heat shock proteins into another alga. We may even go further by having a spectrum of protein production in each alga. So, one alga may produce a few fluorescent proteins and a multitude of heat shock proteins while another could produce a large number of fluorescent proteins and a small number of heat shock proteins. Water Flow We previously thought that corals were very gentle animals that require as little water disturbance as possible. The original plan was to place a coral into a tank with stagnant water. However, Kim Stone informed us that this isn’t the best method. Corals actually need constant water flow to circulate nutrients and prevent sedimentation. In fact, a small number of storms can actually benefit the corals by clearing out some of the sedimentation/pollution and encourage asexual fragmentation to occur. So, we will now place our model organism into a tank with constant water flow. Algae uptake Once our algae have been successfully engineered to resist the stressors that cause bleaching, we will need the coral to uptake them. We thought of several ways of doing this. One way involved dumping a large concentration of our algae into a sea region where a large but stressed coral reef is found. Another possibility was to inject the algae into the coral with a syringe-like tool. After speaking with Kim Stone at the GA Aquarium, we came up with a much more practical solution. We may partner with the GA Aquarium in the future when they can provide us with tank systems that can be regulated with respect to temperature, light intensity, and water flow. We plan on setting up two tanks of seawater. We’ll begin by placing a Caulastraea coral into the first tank. After inducing bleaching by gradually bringing the temperature up 2°F every other day until about 86 °F is reached, we will transfer the organism into a fresh tank. To prevent the coral from going into shock, this fresh tank will start at 86 °F, and its temperature will eventually be brought down to about 72 °F. We will then introduce our algae of varying concentrations and monitor the coral for uptake. If the coral uptakes, we will later observe its offspring and note if the modified symbionts were passed down from the mother.