More coral sex helps restore damaged reefs

A major $1.2 million Australian Centre for International Agricultural Research (ACIAR) grant enabling the world’s first large-scale restoration of damaged reefs using coral larval reseeding has been awarded to Professor Peter Harrison from the Marine Ecology Research Centre at Southern Cross University.

The innovative five-year project in the Philippines builds on a pilot project in which Professor Harrison and colleagues successfully initiated reef restoration through ‘reseeding’ of degraded coral reef sites using millions of coral larvae.

“We have been able to establish new coral colonies on damaged reef areas by growing millions of coral larvae from coral spawn to rapidly increase the settlement of coral larvae. The surviving corals have now grown to dinner plate size after two years and will start spawning next year,” said Professor Harrison, who is director of the Marine Ecology Research Centre.

“This new project is really exciting as it will provide the world’s first large-scale restoration of damaged reefs using coral larval reseeding, and the techniques can be applied to many other reefs around the world including damaged areas of the Great Barrier Reef.”

The research is globally significant because more than 60 per cent of the world’s coral reefs are under direct threat or have been seriously degraded by human activities and some reefs have been destroyed.

“Effective techniques for large-scale coral reef restoration are urgently needed,” Professor Harrison said.

“Corals are the foundation of coral reefs and provide the complex reef structure and habitats for the huge diversity of other reef organisms, and when corals spawn their larvae settle on the reef and renew the critically important coral communities allowing reefs to recover from disturbances. We can now use large coral spawning events to kick start the recovery of important reef areas that are also essential sources of food and income for local people.”

The new research will greatly increase the scale of mass larval reseeding trials on degraded reefs in the northern Philippines that have been damaged by blast fishing, crown-of-thorns seastar outbreaks, typhoons and coral bleaching and will also examine the socio-economic values of large-scale reef restoration approaches.

“Essentially, this research is designed to restore the many natural and socio-economic values of damaged reefs and by doing so will improve the livelihoods of local communities who rely on these reefs for their well-being and survival,” said Professor Harrison.

Photo: Favites brain coral spawning (credit: Peter Harrison).