SYDNEY, Nov 17, 2019 (BSS/AFP) – A mass coral spawning has begun on
Australia’s Great Barrier Reef, with early indications the annual event could
be among the biggest in recent years, local marine biologists said Sunday.
Buffeted by climate change-induced rising sea temperatures and coral
bleaching, the world’s largest reef system goes into a frenzy once a year
with a mass release of coral eggs and sperm that is synchronised to increase
the chances of fertilisation.
Marine biologist Pablo Cogollos, from Cairns-based tour operator Sunlover
Reef Cruises, said the first night of the 2019 spawning was notably
“prolific” in a positive sign for the under-threat ecosystem.
“There was three times the volume of eggs and sperm compared to last year,
when the soft corals spawned four nights after the full moon and it was
deemed to be the best coral spawn in five years,” he said.
The natural wonder, which has been likened to underwater fireworks or a
snowstorm, occurs just once a year in specific conditions: after a full moon
when water temperatures hover around 27 to 28 Celsius.
Soft corals are the first to release, followed by hard corals, in a process
that typically spans between 48 and 72 hours.
Coral along large swathes of the 2,300-kilometre (1,400-mile) reef have
been killed by rising sea temperatures linked to climate change, leaving
behind skeletal remains in a process known as coral bleaching.
The northern reaches of the reef suffered an unprecedented two successive
years of severe bleaching in 2016 and 2017, raising fears it may have
suffered irreparable damage.
Scientists last year launched a project to harvest coral eggs and sperm
during the spawning, from which they plan to grow coral larvae and use it to
regenerate badly damaged areas of the reef.