An Australian marine biologist who's developed a kind of IVF for corals says it holds great promise for sick reefs worldwide.

Southern Cross University Professor Peter Harrison has spent more than 30 years studying the intricacies of coral reproduction. In short, they're not very good at it.

When corals spawn in natural environments, clouds of eggs and sperm float every which way, at the mercy of the currents, winds, and waves.

When eggs and sperm do manage to hook up, the resulting larvae often drift away from reefs and die. And very few of the larvae that do settle on reefs actually take hold and reach breeding age themselves.

But Prof Harrison has found a way to give corals the kind of reproductive helping hand that IVF has given to humans since the late 1970s.

In a world-first breakthrough, he and his team have been able to grow millions of coral larvae in tanks and deliver them onto a blast-damaged reef in the Philippines to create a new breeding coral population quickly.

"This is the first study anywhere in the world that has successfully re-established a breeding coral population from coral larvae settling directly on the reef," he says.

"And the really exciting outcome is that surviving corals grew fast enough to get to a big enough size to start sexually reproducing themselves after three years."

He sees vast promise in the technique and says that with more research and development it can be geared up to make a difference to reef health on a large scale.

That's not true for existing techniques including so-called coral gardening, which relies on breaking apart healthy corals and sticking branches back onto reefs in the hope they'll regrow.

"That's the most widely used technique at the moment but we know it doesn't work very well and sometimes it fails completely."

Prof Harrison is the director of the Ideas Research Institute at Southern Cross University, and is the brains behind the new coral seeding technique.

His experiments on the Philippines reef damaged by blast fishing have been backed by the Australian Centre for International Agricultural Research, which funds research to improve productivity, sustainability and food security in developing countries.