Saving Coral Reefs, One Fragment at a Time

By Rhys Gerholdt, WWF-US

Coral reefs are among the most valuable ecosystems on Earth, providing a home and nursery for 25% of the world’s marine life. For many coastal areas, healthy coral reefs provide an important barrier against destructive storms. In Belize, they are essential to the local economy, which depends on fishing and tourism.

However, roughly one-quarter of coral reefs worldwide are already considered damaged beyond repair, with another two-thirds facing serious threats from overfishing, careless tourism, agricultural runoff, sewage pollution and rising ocean temperatures caused by climate change.

The warmer waters can force algae that lives in coral to abandon their host, depriving coral of its food and its vibrant colors. The coral turns ghostly pale—what we call “coral bleaching”—and is left vulnerable to starvation.

If the current rate of warming continues, coral reefs may be pushed past their capacity to recover.

But there is hope. About 12 miles off the coast of southern Belize, scientists are experimenting with growing and planting coral that are naturally tolerant of warmer temperatures.

Growing Hope Off the Shore of Belize

The experiment began after Hurricane Iris devastated Belize in 2001. Lisa Carne, a young American researcher that moved to Belize in 1995, saw that the reef was literally torn to pieces, littering the sea floor with fragments of coral. But Lisa Carne noticed a promising sign as well: some areas of coral survived and grew back faster than others, indicating that they are more resilient to stresses like hurricanes and unusually warm ocean temperatures.

This gave Lisa the idea to transplant naturally broken bits of more resilient coral upright, using them to reforest damaged areas of the reef.

It took years of sharing her story and convincing fellow scientists that this technique could work, but finally in 2006 things came together. With mentoring from Harold Hudson, a prominent U.S. reef biologist and initial funding from the Protected Areas Conservation Trust, Lisa cemented 19 fragments of Elkhorn coral to the dead reefs surrounding Laughing Bird Caye National Park. A few months later, she returned to the site and, to her great excitement, found that the corals were growing.

Since that initial success Lisa has been taking her experiment to the next level, thanks in-part to funding from World Wildlife Fund.

Coral that are naturally exposed to warmer ocean temperatures are now grown in nurseries, and then harvested and attached to underwater metal structures at the nursery sites where they can grow faster.  When the fragments grow large enough, they are planted in damaged areas of the reef to further thrive and help rebuild the reef. DNA analysis performed in the U.S. helps determine which corals to grow where, ensuring Lisa plants corals that are genetically diverse.

Sea life such as spiny lobsters and an endless variety of fish enjoy the newly grown coral as they are quickly drawn to it and curiously examine the addition to their underwater habitat.

There are now half a dozen coral nurseries off the coast of southern Belize, and over 4,000 corals have been planted aroundLaughing Bird Caye National Park, bringing life back to a region of the reef still suffering from the effects of previous hurricanes.

As threats like climate change reach new heights, the coral nurseries in Belize offer an innovative approach to maintaining healthy coral reefs around which sea life can thrive. Supporting ideas like this is one of the ways WWF and our partners in Belize are building hope for the future of reefs, one fragment at a time.