Baby Corals Can Stimulate Coral Growth In The Great Barrier Reef
For the first time, researchers were able to stimulate the growth of corals through a new technique called "larval reseeding." They say the new technique is less expensive but more effective than other reef restoration techniques.
How Does 'Larval Reseeding' Works?
To test the new method, a team of researchers from the Southern Cross University in Australia headed to the Great Barrier Reef in 2016 to collect large amounts of coral eggs and sperm during mass coral spawning.
Mass coral spawning takes place once every year and involves eggs and sperm being released into the water column all at the same time. This phenomenon was co-discovered by Professor Peter Harrison, lead researcher of the pioneering project.
After collecting the eggs and sperm, the team used them to develop a massive amount of coral larvae, and then placed the larvae on reef patches in underwater mesh tents.
After one year, the team went back to Heron Island in time for the next mass coral spawning and discovered that the baby corals had managed to successfully establish themselves on the reef.
Works Better Than Other Techniques
Harrison said the results they found were very promising. The method they used appears to be more effective than other reef restoration techniques such as coral gardening.
Coral gardening involves fragmenting healthy wild corals, growing them in underwater nurseries and then, transplanting them onto the reef. Harrison added that this is the most widely used technique in other reef regions, but it is more expensive and sometimes, a complete failure.
In addition to coral gardening and larval reseeding, there is another technique called "reef balls" in which artificial concrete structures are built and used to protect natural reef systems.
Major Drivers Of Reef Decline
Researchers said the new restoration technique offers new hope, but it does not mean that it will reduce the major drivers of reef decline such as climate change and pest management.
"In recent years, the impacts of climate change on the Great Barrier Reef have undoubtedly accelerated, as we saw with back-to-back years of coral bleaching. It is vital everyone keeps working to address climate change and build the Reef's resilience, and for restoration strategies to be developed that can work over large areas," said Great Barrier Reef Marine Park Authority Chief Scientist David Wachenfeld.
According to scientists, about 70 percent of the world's reefs have been affected by global warming and the majority of reefs in the United States could die out within 20 to 30 years. A March 2016 report revealed that coral bleaching was more widespread than previously thought, affecting the northern parts of the Great Barrier Reef as a result of global warming.
Bleaching struck 90 percent of coral on the Great Barrier Reef and killed around 29 to 50 percent of the reef's coral in 2016. Coral bleaching is a phenomenon that takes place when the ocean's waters increase in temperature due to carbon dioxide exposure. When the temperature rises, the reef's algae cannot manage to survive, so they eventually die off. When they die off, the reefs also die.