Spawning coral release quintillions of eggs each year: new research

Auscape / Getty Images Most kinds of coral spawn once a year .

In an enormous multi-day event synchronised to specific phases of the moon, they release vast slicks of eggs and sperm into the ocean to be mixed together by the drifting currents.

Imagine hundreds of thousands of Olympic swimming pools filled with tiny pinkish spheres, all dumped into the sea at once.

In new research published in Ecology and Evolution, my colleague and I have for the first time estimated just how many eggs are involved in one of these spawnings, and it’s a mind-boggling number.

According to our calculations, in a single spawning event, corals across the Indo-Pacific region release around 3.5 quintillion eggs (that’s 3,500,000,000,000,000,000 if you write out all the zeroes).

This isn’t a just a curious piece of trivia, either: it’s basic information we need to help preserve Earth’s coral species for the future.

Coral spawn form large pinkish slicks in the ocean.

Credit: Philippe Max Rouja.

Why count coral eggs? Counting Earth’s ecological assets reveals how our planet functions.

Knowing the total number of ants living in the ground (around 20 quadrillion) allows scientists to estimate how much carbon they can remove, for example.

Scientists have mapped half a trillion adult coral colonies , as well as tracking global fish egg production .

These numbers tell us about the function and health of ecosystems.

Counting nature also tells us about its power to regenerate.

Ocean life, and coral reefs in particular, are bearing the brunt of global warming.