Podcast

Coral in crisis: Coral are marine invertebrates formed from colonies of polyps. Coral bleaching occurs when coral loses its pigment, expels zooxanthellae, and turns white. Declining coral reefs decrease biodiversity and can cause erosion. Global bleaching events are widespread coral bleaching on a large scale. Without coral, reefs die and can't reproduce, affecting wildlife and ecosystems. Coral bleaching contributes to climate change as it releases more CO2 into the atmosphere. Hello, my name is Riley Humphrey and I'm here with Gabrielle Chagall and Sarah Abbey. We are Sustainabaggle and this week's episode is about coral in crisis, how coral bleach can kill the ocean, and to help us is our senior marine biotechnologist for CCIW, Daniel Abbey. Our first question for you, Daniel, is what is coral? Coral are marine invertebrates that are formed from colonies of polyps. Each polyp is a sac-shaped animal that are very small with tentacles surrounding their mouth. Over time, each polyp will create an exoskeleton around their base, which is a skeletal structure we see as coral. Very interesting. That actually leads us into our next question. What is coral bleaching? Coral bleaching is a process with which coral turns white and is essentially the death of the coral structure, and this happens when it loses its pigment. Coral bleaching occurs when zooxanthellae lose their ability to photosynthesize due to a raise in temperature. So the coral expels zooxanthellae, essentially starving itself. With the increased water temperature, the zooxanthellae produces reactive oxygen species. This is poisonous to the coral, and so they expel zooxanthellae, causing the coral's color to disappear. I have a question. How does the disappearance of corals affect aquatic ecosystems? Coral reefs provide essential habitats for a number of animals, like fish, sponges, invertebrates, and mollusks. The declining coral reefs can result in a decrease in biodiversity. Additionally, they absorb wave energy, which helps protect coastlines from erosion from wave action. Well, what is a global bleaching event? Large-scale bleaching events can be defined as widespread coral bleaching of coral reefs, such as the Florida Reef Tract, the Eastern Pacific Coral Reef, the Amazon Reef, or the Great Barrier Reef. When this happens, the temperature of the ocean rises too quickly and on such a large scale that a wide-scale bleaching of the reef occurs. How does this affect us? What are the long-term effects of coral bleaching? Without coral, the reefs die and can't reproduce and come back. Since coral is responsible for most of the biodiversity in these reefs, taking the coral away from that causes a chain reaction that has a negative effect on the wildlife and ecosystem around it. To wrap this up, our final question today is how does coral bleaching affect climate change? The change in temperature in the ocean due to climate change is causing coral bleaching. The zooxanthellae collected by the polyps on the coral photosynthesizes and absorbs CO2 from the ocean. Without the coral, more CO2 gets released into the atmosphere and results in a positive feedback loop. This is something we really need to stop. Thanks for all your help, Daniel. No problem. Oh, this is sustainable. Thanks for listening. Go.