Corals grown in Australia’s first offshore coral nursery at Fitzroy Island off the country’s northeast coast are ready to spawn for the first time after being planted on the Great Barrier Reef four years ago, but are keeping their proud parents waiting for the big reveal.
The team at the not-for-profit Reef Restoration Foundation had hoped to see thousands of tiny pink bundles of eggs and sperm erupting from branching acropora corals planted in Welcome Bay on October 14th.
However, Master Reef Guide and marine biologist Azri Saparwan, who helped to plant the corals in 2018, said the inshore hard corals including nearby hard corals that had grown naturally on the reef were holding onto their bundles of sperm and eggs:
“We did see spawn coming from the soft corals which is usually a pre-cursor to the hard corals spawning.
“In the past few years Fitzroy Island has always spawned in October, but the full moon was a bit earlier this year so the inshore reefs may not spawn until the full moon in November.
“The conditions were good for spawning last night with calm 28C water and a big slack tide so there wasn’t much movement on the surface, but we have had cloudier conditions and some rain in October which is unusual and may have delayed the spawning.
“It was still a great night dive with the spawn from the soft coral and plenty of fish to see on a healthy reef system.”
Reef Restoration Foundation Chief Executive Officer Ryan Donnelly said his team of marine biologists and a coral farming expert would be back again after the November full moon to see if the hard corals spawn:
“We broke open fragments of the corals that we had planted and discovered that they were ready to spawn, but other variables have not lined up for spawning.”
The inshore reefs off Cairns tend to spawn a month ahead of the outer Great Barrier Reef where the sheer volume of corals reproducing creates big slicks of spawn on the water.
The outplanted corals at Fitzroy Island were grown on underwater frames after the Great Barrier Reef Marine Park Authority granted a permit for a pilot research offshore nursery at Fitzroy Island in 2017.
“We planted coral cuttings in a degraded patch of reef and these pioneer species have grown to around 1m in diameter helping to create a healthy and complex habitat for various corals and marine life.”
Cameron Bee, who has 25 years’ experience in coral aquaculture, creating coral farms around the Asia-Pacific region and is part of the Great Barrier Reef Legacy’s Living Coral Biobank project to preserve coral diversity, was part of the team hoping to record the coral spawning:
“We are facilitating reef recovery in a time when disturbances are more frequent and severe. Growing corals to create habitat is important but additionally taking them through to spawning is a milestone in our bid to maintain biodiversity.”
Stay tuned in November to see whether the corals spawn during that month’s full moon.