Coral relief
Scientists in Hawaii use ‘assisted evolution’ in hopes of breeding reefs that can withstand global warming
COCONUT ISLAND, HAWAII— Scientists at a research centre on Hawaii’s Coconut Island have embarked on an experiment to grow “super coral” that they hope can withstand the hotter and more acidic oceans that are expected with global warming.
The quest to grow the hearty coral comes at a time when researchers are warning about the dire health of the world’s reefs, which create habitats for marine life, protect shorelines and drive tourist economies.
When coral is stressed by changing environmental conditions, it expels the symbiotic algae that live within it and the animal turns white or bright yellow, a process called bleaching, said Ruth Gates, director of the Hawaii Institute of Marine Biology.
If the organisms are unable to recover from these bleaching events, especially when they recur over several consecutive years, the coral will die. Gates estimated that about 60 to 80 per cent of the coral in Kaneohe Bay, off the island of Oahu, has bleached this year.
“The bleaching has intensified and got much more serious,” said Gates of the coral around the bay. Where they once looked for the bleached coral among the healthy, Gates said her team is now “looking for the healthy individuals in a sea of pale coral.”
Gates and her team are taking the coral to their centre on the 12-hectare isle, once a retreat for the rich and famous and home to television’s Gil
ligan’s Island, and slowly exposing them to slightly more stressful water.
They bathe chunks of coral that they’ve already identified as having strong genes in water that mimics the warmer and more acidic oceans. They are also taking resilient strains and breeding them with one another, helping perpetuate those stronger traits.
The theory they are testing is called assisted evolution, and while it has been used for thousands of years on other plants and animals, the concept has not been applied to coral living in the wild.
“We’ve given them experiences that we think are going to raise their ability to survive stress,” Gates said. She said they hope to see these coral, which will soon be transplanted into the bay, maintain their colour, grow normally and then reproduce next summer.
In early October, the National Oceanic and Atmospheric Administration said that coral reefs worldwide are experiencing bleaching, calling the event extensive and severe.
“We may be looking at losing somewhere in the range of 10 to 20 per cent of the coral reefs this year,” NOAA coral reef watch co-ordinator Mark Eakin said when the report was released. “Hawaii is getting hit with the worst coral bleaching they have ever seen.”
And this is the second consecutive year Hawaii has experienced widespread bleaching.
Scientists say some coral has already fallen victim to global warming. About 30 per cent of the world’s coral has already perished as a result of above average ocean temperatures, El Niño’s effects and acidification.
Gates and her team understand the challenges of scalability and time. Having success locally does not necessarily mean they will be able to scale their project to address a massive, global marine crisis before much of the world’s coral reefs are already gone.