Southern Cross University Professor Peter Harrison helps project on Magnetic Island on the Great Barrier Reef where scientists have been clearing algae to transplant coral babies back onto the reef.
Southern Cross University Professor Peter Harrison helps project on Magnetic Island on the Great Barrier Reef where scientists have been clearing algae to transplant coral babies back onto the reef.

UNDERWATER STORM: Scientist's new plan to save coral reefs

WHEN Professor Peter Harrison first snorkelled at reefs on Magnetic Island in the 70s, he was surrounded by millions of coral species.

Now, he said, the once colourful reefs are dominated by seaweed.

But Prof Harrison is part of a team of scientists who are releasing coral 'babies' on the Great Barrier Reef (GBR) as part of a watery war to fight algae choking parts of the renowned site.

 

Geoffrey Bay site.
Geoffrey Bay site.

The problem is particularly bad on inshore reefs including Magnetic Island, eight kilometres off the Townsville coast, due to poor water quality, increased nutrients and bleaching events.

Along with researchers James Cook University and the Australian Institute of Marine Science (AIMS), they have combined decades of experience to trial the new approach to restoring inshore reefs around Magnetic Island in the Central GBR.

 

Rearing coral larve at AIMS.
Rearing coral larve at AIMS. Mark Walsh

The scientists have been clearing algae that has been choking sections of the reef, making room for Prof. Harrison's team from Southern Cross University to deploy millions of coral larvae to resettle the coral babies on the reef in a process known as 'coral IVF'.

 

Cluster of baby corals newly settled.
Cluster of baby corals newly settled.

 

Branching coral larve looking for a site to attach and settle.
Branching coral larve looking for a site to attach and settle.

It's almost 38 years to the day at the same location since Prof Harrison and colleagues discovered the mass coral spawning natural phenomenon, which is akin to billions of coral eggs and sperm being released into the sea simultaneously and spectacularly like an "underwater snow storm".

The discovery radically changed scientific views about how corals on the Great Barrier Reef, and other reefs around the world, reproduce.

The first coral spawning of the 2019 season began in the evenings of October 18 and 19 and since then the Southern Cross University team has collected the coral spawn and grown millions of coral larvae in rearer pools for an experiment to resettle the babies on the reef.

 

Southern Cross University Professor Peter Harrison with team members from SCU and JCU on Arthur Bay reef.
Southern Cross University Professor Peter Harrison with team members from SCU and JCU on Arthur Bay reef.

"Our previous extensive reef trials have shown that supplying coral larvae to degraded reefs can rapidly restore breeding coral populations within a few years, and for this new collaborative project we're examining how effective the combination of algae removal and larval restoration can be," Professor Harrison said.

"I'm pleased by the initial rates of larval settlement we're seeing so far and we'll be monitoring the reef sites over coming months to see how many new juvenile corals become visible next year."