Oceans and  Coasts

Resilience: Keeping the Pacific's Coral Reefs Alive

Helping coral survive in a high-traffic area on Hawaii Island

75 percent of the world's coral reefs are under threat.

By Lisa Leone

Each year, coral reefs around the world are deteriorating due to threats like overfishing, pollution, introduction of foreign species, costal development and climate change.

In fact, a new report, Reefs at Risk Revisited, shows that 75 percent of the planet’s reefs are threatened by these factors.

Still, there is hope for these beautiful habitats because of their resilience.

Hope in Hawaii

Some reefs in Hawaii are not just being preserved—they’re actually experiencing regrowth. In the Kaneohe Bay, a high-traffic area on Hawaii Island where alien algae species are suffocating corals, The Nature Conservancy and its partners have stepped in with solutions. The result: substantial increase in coral cover in the past year and a half.

“For the first time, this many-year trend of loss of coral is reversed, and the algae is gone and the coral is coming back,” said Eric Conklin, the Conservancy’s marine science advisor in Hawaii.

The removal efforts have been two-fold:

These measures allow the Conservancy and its partners to reset the corals to what they should be. “In a lot of instances, coral reef conservation is about stopping things, like overfishing or causing physical damage to the reefs. This is one of the few examples of actively doing something that achieves restoration,” Conklin said.

A Model of Perfection in Palmyra

Conservancy experts like Conklin have a unique perspective on reef restoration because of their experience studying a nearly untouched, 1,600-acre reef at the remote Palmyra Atoll 1,000 miles south of Hawaii.

“It’s how a tropical reef should look,” said Kim Hum, director of the Conservancy’s Hawaii marine program. Palmyra’s reef hosts a balanced ecosystem with a full complement of species, whereas others around the world no longer have the fish and large predators seen in a healthy reef.

“Having a couple of places in the world where we can see what a healthy reef looks like gives us a target to shoot for,” Hum said.

It also gives researchers the rare opportunity to study what problems are most harmful to reefs, since Palmyra does not have the multiple local stressors present in more populated areas:

  • Researchers studying the effects of sedimentation alone on the reef found that unstressed corals could survive.
  • Palmyra’s healthy reefs were able to recover from a bleaching incident.
  • Coral disease—often a fatal blow to most reefs—occurs on a much smaller scale. One of the only noted cases of fatal coral disease followed a bleaching incident, showing that the result was due to the already stressed and weakened state of the coral.

The Conservancy works at Palmyra as part of the Palmyra Atoll Research Consortium and sends four to six researchers on three-month rotations to the remote locale. The Conservancy is also undertaking a Pacific-wide monitoring program to compare reefs in places such as Hawaii, Palau and Indonesia that have varying uses and stressors. This way, researchers will be able to determine longer term impacts of various stressors.

The Key to Resilience: Education

Back on the islands of Hawaii, the Conservancy works to educate communities along the reefs, teaching the importance of:

  • Responsible fishing
  • Implementing management
  • Protected areas
  • Physically removing invasive algae

Although a state-conducted survey of Hawaiian reefs over the past 10 years determined that, in general, coral cover in Hawaii is declining, it also discovered that on the west coast of Hawaii Island, the coral is growing and thriving. A network of protected areas along 30 percent of this coast is most likely the reason, and the Conservancy’s work with the communities there has surely helped.


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