Instantly recognizable by their varied textures, unique shapes and community reef systems, corals are stunning living organisms. Scientists hope that by growing new coral colonies – a process called coral aquaculture – they can maintain and sustain coral for public display and help conserve endangered coral species.
Recently I chatted with Kim Hall, Associate Curator of Fish & Invertebrates at the Georgia Aquarium, to learn more about this process. She explained that the “intention is to maintain and continue to add to the current coral collection in a display environment and become self sustaining. This allows us to educate the public about the animals without impacting their natural environment by collecting form the wild. Aquariums across the country also exchange corals to better the genetic stock of the animals within all of our collections.”
Additionally, coral aquaculture can play a pivotal role in conservation. Corals are an endangered, carnivorous invertebrate species with numerous threats to their existence, like pollution, global warming and sedimentation. Kim shared that the Georgia Aquarium is working in collaboration with various organizations (such as Georgia Technological Institute and the EPA) with the study of invasive species of coral. “The Sun cup Coral has made its way from the Indo Pacific into the Caribbean and could have a major impact on the native species,” said Kim. “And another conservation project that we will be involved with is SECORE. It’s name is derived from the phrase SExual COral REproduction, and is an initiative of public aquariums and scientists to carry out research to advance conservation of coral reefs worldwide… This project includes conservation work with a species of coral (Acropora palmata) in the Caribbean that is considered critically endangered.”
By assisting the SECORE project, the Georgia Aquarium hopes they are able to grow Acropora palmata on-site for potential reef restoration work back out on the natural reefs. Kim explained that currently they “propagate or frag corals after they have gone through quarantine and are ready to be placed in the main exhibits. A frag is essentially a fragment that is safely cleaved off of a larger specimen. We keep the small frags in the holding tank and allow them to grow before continuing the same process. The current species that we are cultivating now are: Montipora sp., Montipora digitata, Seriatopora hystrix, and Pocillopora damicornis.“
Specific tools and equipment are necessary for successful coral aquaculture study. A large pool facilitates the cleanliness of the tank that the corals are in. As Kim shared with me, “It’s very important to have the system be as clean as possible… It is a constant battle with the amount of light you need for their growth and the zooxanthellae that grows within their tissue.”
Appropriate lighting is another essential component to the coral aquaculture process, as corals generally live near the surface in warm, tropical waters, where plentiful sunlight encourages algae growth. Healthy corals feed on algae byproducts, zooplankton and even small fish.
A source of natural sunlight – such as a skylight – promotes successful coral aquaculture results, according to Kim’s first-hand experiences. “At the Georgia Aquarium… We are very fortunate to have a natural sunlight source provided to the corals by the skylight that is over the exhibit… [but] we do have to supplement the sun with artificial lighting to compensate for the intensity of the sun that changes throughout the year and the spectrum of light that the sun provides. The lights that you see in the picture (below) are four 1000 watt metal halides that have a spectrum of 14 Kelvin. This gives the corals a more bluer color to absorb in addition to the sun.”
Although coral reefs cover less than one percent of the seafloor, they are incredibly important aquatic habitats as they sustain 25% of all marine animals.
Photo Credit: Jodi Kendall