In a new study conducted by researchers at the Woods Hole Oceanographic Institution (WHOI) and King Abdullah University of Science and Technology (KAUST), there is new evidence of a complex symbiotic relationship between certain species of reef building coral and bacteria that wasn't previously understood. It has been known that many coral form symbiotic relationships with many other organisms, such as algae. Researchers have already understood that a species of reef building coral, Stylophora pistillata, hosts a group of bacteria called Endozoicomonas. However, where these bacteria live and what they do for the coral isn't well known.
The first challenge is to discover where these microbes are located within the coral. This was accomplished by marking the bacteria's genes with a fluorescent tag. This will be specific for this bacteria and no other microbes will be detected. Therefore, once the researchers scan for fluorescence, glowing bodies, they can locate where the bacteria live. This knowledge will then help researchers begin to understand the type of communities they form and how they may benefit the coral. The result was that these microbes were observed living deep within the coral's tissues in clusters like “grapes on a stem”. This is the first time this group of bacteria have been shown to live within a marine animal.
The next step is to study what this symbiotic relationship really mean. What does this bacteria community, which also make up a good portion of the coral's biomass, do for the coral? Many researchers believe that the bacteria may aid in recycling nutrients in order to keep the coral healthy. It is important to understand this relationship because coral face many dangers such climate change, destruction by humans, and diseases. Having a strong grasp on its ecology will help in conservation efforts.