The Disappearing Rainforests of the Sea

Audience: Middle and High School Students

Despite the fact that coral reefs cover less than 1% of the ocean floor, they support about 25% of all marine life! Photo by Getty Images from Unsplash. 

Hidden beneath the ocean’s surface lies a vibrant world of natures underwater cities, made up of hundreds of thousands of coral reefs. Coral reefs are like the oceans' living cities, full of color, motion, and numerous dwellings for marine life to reside. However, these crucial marine structures are currently in peril due to the selfish actions of humans. Coral reefs are large, underwater structures made by tiny animals called coral polyps. These polyps build hard skeletons of calcium carbonate, which is the same material shells are madeof. Over time the calcium carbonate deposited by the coral polyps will accumulate to form a coral reef. Most corals live in warm, shallow waters, relying on the special mutualistic relationship they have with algae to thrive. A mutualistic relationship is one where both parties benefit from the relationship. In this case, algae gain a safe and stable environment to live in within the coral. Meanwhile, the coral receives compounds rich in energy like glucose, that helps them build their skeleton and reproduce. 

Now despite what many people think, coral reefs are much more than just a pretty sight, they are crucial in the preservation of marine life. In fact, coral reefs house about 25% of all marine life. They provide shelter, breeding grounds, and protection for thousands of marine species such as fish, crustaceans, and even turtles. Furthermore, many marine species also depend on coral reefs as a source of nutrition. Some animals feed on algae present in  coral reefs, while others feed on the small organisms that live around the area. However, what many people don't realize is the benefits of coral reefs extend past the animals that live within them. They also play a crucial role in protecting coastlines by acting as a natural barrier in the water, absorbing wave energy which reduces coastal erosion, the gradual wearing away of land along the coastline. The erosion of this land can lead to the loss of beaches, properties along the water, and even important habitats like mangroves and wetlands. 

Coral bleaching is a damaging process where coral reefs begin to turn white and as a result are dying. This occurs when corals become disturbed and begin to expel the algae known as zooxanthellae, which resides inside them. The algae that dwells inside corals is critical to their survival, because it provides the corals with the energy they need to survive, through the process of photosynthesis. The algae inside the coral undergo photosynthesis, which is the process of converting sunlight into sugars and other nutrients that the coral needs to thrive. Therefore, as corals expel algae, they begin to lose their energy provided by photosynthesis as well as their pigment provided by the zooxanthellae. The loss of algae that causes coral bleaching can be linked to a variety of factors, but regardless of how it occurs, it is harmful to the survival of coral and the marine life that surrounds it. 

The leading cause of coral bleaching is rising sea temperatures, however other issues such as pollution from agricultural runoff, increased UV radiation due to the depleted ozone layer, and ocean acidification can also lead to coral bleaching. Fortunately, there are ways to combat coral bleaching in order to protect coral reefs. For example, reducing global greenhouse gas emissions can help slow climate change down, which in turn minimizes ocean warming. Additionally, marine protected areas are being established to protect reefs from activities such as overfishing, giving coral reefs the ability to thrive. These are a popular initiative, but scientists have not stopped there. Currently, they are also working to develop new and improved ways to protect coral reefs. For example, the Great Barrier Reef Foundation has been trying to grow heat resistant coral in nurseries. They implant these artificial reefs onto struggling coral reefs in order to make them more resilient and give them a better chance at thriving, despite living in non-ideal conditions. 

Now, for obvious reasons, the average person can't grow heat resistant coral reefs in their backyard. However, there are still things anyone can try to help protect coral reefs. One of the most effective strategies is reducing your carbon footprint. This can be done by using more energy efficient appliances, driving less, and supporting the use of clean energy. Cutting down on single-use plastics and recycling properly also play a crucial role in protecting coral reefs, because plastic waste often ends up as ocean pollution. Another very important step that you can take to protect coral reefs is reducing harmful runoff. This can be done by using less harmful household chemicals and minimizing the use of fertilizer in your lawn. Lastly, a lesser known, but critical way to protect coral reefs is practicing safe snorkeling and scuba diving around these areas. You can do so by not touching, standing, or taking anything from coral reefs, and using reef-safe sunscreen to help protect the reefs from harmful chemicals. By making small, conscious choices in our daily lives, we can all contribute to the protection and preservation of coral reefs. Ensuring that these vital ecosystems continue to thrive for generations to come. 

Bibliography: 

Loiacono, Milan . “What Is a Coral Reef? - NASA.” NASA, 16 Oct. 2024, www.nasa.gov/general/what-is-a-coral-reef/. Accessed 16 June 2025.

National Oceanic and Atmospheric Administration. “The Importance of Coral Reefs - Corals: NOAA’s National Ocean Service Education.” Oceanservice.noaa.gov, National Ocean Service, 12 Aug. 2024, oceanservice.noaa.gov/education/tutorial_corals/coral07_importance.html. Accessed 16 June 2025.

---. “What Is Coral Bleaching?” Noaa.gov, NOAA, 16 June 2024, oceanservice.noaa.gov/facts/coral_bleach.html . Accessed 16 June 2025.

United States Environmental Protection Agency. “Threats to Coral Reefs.” US EPA, 2024, www.epa.gov/coral-reefs/threats-coral-reefs. Accessed 16 June 2025.

US EPA. “What You Can Do to Help Protect Coral Reefs | US EPA.” US EPA, 22 June 2023, www.epa.gov/coral-reefs/what-you-can-do-help-protect-coral-reefs. Accessed 16 June 2025.