Restoring Coral Reefs

Coral ecosystems are dying in oceans around the world, with 30-50% of coral reefs lost due to pollution, rising temperatures, invasive species, and more. Coral reefs are a key part of the oceans they inhabit because both animals and people depend on corals for a multitude of reasons including food, livelihoods, economic benefits, and culture. Corals also contribute around 10 trillion dollars globally to tourism and fishery. Hence, this begs the question of what steps can be taken to halt their destruction and restore these key habitats.

While there are many other organizations that focus on coral reef restoration, the National Oceanic and Atmospheric Administration (NOAA) focuses on four particular strategies: improving habitat quality, preventing loss of habitat, enhancing coral resilience, and improving coral health and survival. The NOAA is working on planting coral nurseries on underwater structures, with 20 coral nurseries already active throughout the Caribbean. surveying how healthy the habitat is for coral growth, and building coral resilience to climate change. As the NOAA collects detached corals that are either broken fragments or fully-formed colonies, it works with partners to grow them into dense nurseries. When grown and healthy, the corals are transplanted back into reefs with cement, zip ties, and nails. Also, the NOAA responds to emergencies like ship grounding where the physical impact of a ship on seabed or side of a waterway disturbs and harms corals. This efficiently and effectively helps to save tens of thousands of coral a year.

As many coral reefs are inundated with non-native invasive species and algae that grow and block sunlight from reaching the corals, numerous agencies are working to clear and remove these invasive species through the introduction of native predators. An additional threat to coral reefs is the loss of herbivores like sea urchins and grazing fish which feed on the algae keeping algae numbers under control.

A major example of human intervention in coral restoration is being implemented in the Florida Keys where the NOAA is taking steps to increase coral cover, the percentage of a reef’s surface that is covered by living coral. Previously, coral cover in the Keys were 30-40%, but as of now it has plummeted to 2%. NOAA is removing invasive species and introducing disease-resistant corals in this area in an attempt to reach up to 15% coral coverage. For example, the reintroduction of the elkhorn coral, a species that grows quickly and is not susceptible to stony coral tissue loss disease, is helping to develop the habitat for the future. Additionally, the NOAA plans to improve the coral diversity by restoring star, brain, pillar, and staghorn corals. Finally, by ensuring there is a healthy population of sea urchins and king crabs that eat algae, they were able to regulate the levels of algae in the water. Eventually, NOAA hopes to achieve 25% coral cover in the Florida Keys using this method.

New techniques have been developed over the past few years to mass produce healthy corals. Researchers at the Reef Restoration and Adaption Program (RRAP), the world’s largest R&D program to protect an ecosystem from climate change, have come up with semi-automated and robotic methods to grow thousands of corals to tens of millions. The organization’s goal is to help to increase implementation of coral restoration at a global scale and give the coral reef ecosystems a fighting chance.

However, with 2024’s Earth’s surface and ocean temperatures at a record-high in the NOAA’s 175-year climate record, we must become increasingly aware of our ever-changing environment and the actions we must take to have a chance at restoring balance in coral reef communities. By disseminating knowledge on how one can reduce pollution, overfishing, and hence climate change, we move towards creating a more educated and proactive community.