Restoring Coral Reefs
Coral reefs provide coastal protection for communities, habitat for fish, and millions of dollars in recreation and tourism, among other benefits. But corals are also severely threatened by rapidly worsening environmental conditions. Learn how NOAA works to restore these valuable habitats.
Why Corals Need Our Help
Corals are extremely valuable, contributing about $10 trillion a year globally and more than $3 billion a year domestically to the economy. Hundreds of millions of people depend on coral reefs for food, livelihoods, cultural practices, and a variety of economic benefits. Corals also provide habitat for fish and other marine species and protection for valuable coastal infrastructure.
Coral reefs are damaged due to changing water temperatures, ocean acidification, pollution, invasive species, changing weather patterns, and physical impacts from ship groundings and storms.
The world has lost 30 to 50 percent of its coral reefs already. Without significant intervention, tropical reef ecosystems could face global extinction by the end of the century.
A Plan to Save Coral Reefs
Saving and restoring the world's coral reefs requires a multi-pronged approach that ranges from the local to the global level. Despite notable successes at the local level, we still have a gap to make significant impacts at the ecosystem level. To close this gap, we need to increase resources dedicated to restoration. At the same time, we need to significantly increase the efficiency of every dollar spent and every minute a diver spends underwater. This will require new ways of thinking and advances at a quicker pace than we have seen to date.
The NOAA Coral Reef Conservation Program leads the agency’s coral research, conservation, and restoration efforts. The program’s strategic plan outlines a framework for reducing the main threats to coral reef ecosystems: climate change, fishing impacts, and land-based sources of pollution. The plan also recognizes coral reef restoration as an important focus and the fourth “pillar” of the program.
Within this restoration pillar, NOAA’s work focuses on four strategies:
- Improving habitat quality for corals. This includes supporting research and development of activities that will reduce nuisance and invasive species that compete with corals for habitat.
- Preventing loss of corals and their habitat. Identifying high-risk areas, supporting emergency response, and recovering damages from physical events such as vessel groundings all play a role in reducing damage to coral reefs.
- Enhancing coral population resilience. Research and development of innovative techniques will help improve the resilience and reduce the mortality of coral larvae. In addition, we are building partnerships to help conduct restoration at ecologically meaningful scales.
- Improving coral health and survival. Improving techniques that control the spread of coral diseases and reduce the impacts of organisms that feed on corals will help improve survival rates for corals at key reef sites.
How We Restore Coral Reefs
Coral restoration can take on a number of forms. It can range from simple growing, gardening, and outplanting to harvesting millions of naturally-produced eggs and sperm to create millions of new genetic individuals.
The NOAA Restoration Center works with other NOAA offices and partners to help corals recover. Our efforts include activities such as:
- Planting nursery-grown corals back onto reefs.
- Making sure habitat is suitable for natural coral growth.
- Building coral resilience to threats like climate change.
Growing and Planting Healthy Corals
NOAA facilitates, leads, funds, and implements efforts to grow corals in protected conditions. We work with our partners to collect detached corals—whether broken fragments or fully-formed colonies—and grow them in dense coral nurseries. The corals are then reattached to reefs piece by piece with cement, zip ties, and nails.
More than 20 coral nurseries are active throughout the Caribbean. Each year, they provide more than 40,000 healthy corals for reef restoration throughout the region. Active reef restoration is relatively new in the Pacific Islands Region (Hawaii, Guam, the Northern Mariana Islands, and American Samoa). Efforts are focused on working with local resource managers to develop restoration plans to increase capacity.
NOAA is also exploring the use of innovative techniques for growing and planting resilient, genetically diverse populations of key coral species that can adapt to evolving environmental conditions. A recent NOAA-commissioned study evaluates how novel interventions could accelerate natural evolution and buy coral reefs time to adapt while ocean conditions continue to change.
Removing Invasive Species
Many coral reefs are overrun with non-native algae, which smothers coral and blocks light from getting to them. Through algae removal and reintroduction of natural predators, we clear the invasive species and help coral reefs thrive.
Responding to Emergencies
NOAA established a contract-based emergency response system to address ship groundings and other physical impacts to corals. This system has responded to hundreds of incidents, saving tens of thousands of corals.
Where We're Making a Difference
The NOAA Restoration Center serves as a lead on coral restoration work, participating in a diverse set of coral-related restoration activities across the Caribbean and Florida, as well as within the Pacific sub-basin. We work with the NOAA Coral Reef Conservation Program, the Damage, Assessment, Remediation, and Restoration Program, and other NOAA offices.
NOAA and partners are working to implement Mission: Iconic Reefs, a first-of-its-kind approach to restoring corals at seven ecologically and culturally significant reef sites in Florida Keys National Marine Sanctuary. By the end of this effort, coral cover across the seven sites will be restored from 2 percent to an average of 25 percent.
More broadly, we work with our partners to grow and plant staghorn and elkhorn coral to restore reefs damaged by bleaching, hurricanes, groundings, and disease. One NOAA-supported project produced more than 30,000 branching corals, far exceeding the initial goal of 12,000 coral colonies. These survivors also recovered from bleaching, which suggests they are more resilient to the stresses that cause it.
After Hurricanes Maria and Irma in 2017, NOAA became involved with a FEMA recovery mission assignment focused on coral assessment and response after the hurricanes. To date, more than 10,000 broken corals have been reattached.
After Hurricane Matthew, we rescued nearly 7,000 coral fragments that were damaged by the storm. We identified areas of the reef that suffered major impacts and collected thousands of coral fragments that had broken off. We stabilized them by lodging them in crevices or cementing them to the hard bottom of the reef.
Three years later, monitoring of the restored reef revealed healthy, thriving corals with survival rates at more than 90 percent. Learn more about coral restoration following Hurricanes Irma and Maria through this interactive story map.
NOAA and the State of Hawaii pioneered a method to use native sea urchins and a form of sea-vacuuming to free an urban reef from algal overgrowth. In Hawaii’s Kaneohe Bay, reefs were overgrown with algae, blocking life-giving sunlight and smothering the corals. After careful study, we used an underwater vacuum nicknamed the “Super Sucker” to suck invasive algae off the reef. Then, we released a native algae-eating sea urchin that chowed down on the invasive algae, restoring life and color to the reef.
To further prevent reefs from being smothered, we also work to reduce runoff of sediment and other pollutants from nearby land, which can feed algae growth. For example, in the West Hawaii Habitat Focus Area, NOAA has worked with partners to install fencing to remove feral goats in the watershed. These goats eat native plants, disturbing the soil and contributing to increased sediment runoff to the reef.
NOAA works with partners across the country to address the complex nature of threats facing coral reefs. We provide technical support and funding for coral restoration through programs such as the:
- Coral Reef Conservation Program
- Damage, Assessment, Remediation, and Restoration Program
- Community-based Restoration Program
We help state and local organizations conduct coral restoration projects in their communities. We also establish partnerships with local organizations, state governments, and federal agencies. This enables us to effectively leverage funding and build local capacity and stewardship to restore and improve coral reef ecosystems.