New technique could help head off coral bleaching

STORY: This is ‘soft’ coral, also known as octocorals – they’re the under-researched and overlooked cousin to your classic hard coral but no less important.

A marine biologist in Australia, Rosie Steinberg, has developed a new technique to protect it better.

"Soft corals are often understudied but soft corals are still super important. They provide tonnes of food and shelter for other species. They grow really quickly, so they're good at recolonising after a major disturbance such as a big cyclone or a bleaching event, and honestly they're just beautiful and they deserve all the research that hard corals get."

Steinberg’s technique is based on doing a soft coral ‘health check’, this identifies which corals are most in need of protection from marine heatwaves.

"If you tried to just protect everything all at once, you'd run out of money in ten seconds. You'd run out of money, you'd run out of people, you'd run out of everything that you need, all your resources. So you need to know specifically, yes these are the species that we need to protect, these are the species that are going to be fine no matter what we do, and that's kind of the importance of going through and looking species by species by species."

How does a health check work?

The first step is to grind up wet frozen soft coral samples to create a sort of puree.

"You blend them down, and then you put them in a centrifuge, which is basically a giant box that spins them super fast. And what that does is it pulls down the heaviest things, which are the algal cells, and leaves all of the other stuff like the coral protein up in the water. In that way, I could take the cells out and count them and I could keep that water which has all the protein in it and see how much protein was in the corals as well."

The levels of protein, cells of algae, and chlorophyll all indicate how healthy the coral is.

Steinberg’s research shows that generally soft corals took longer to bleach than hard corals.

Steinberg hopes that the ease of this new technique will encourage more scientists to include octocorals in their research which will create a better overview of the status of reefs.

She says the technique can also be used to identify the health of other marine animals that use algae.

"There's so many marine animals that use algae, there's jellyfish and there's anemones and there's sponges and there's tonnes of stuff and all of them can bleach; every single one. So it is important to have these techniques that aren't just for the main species that we look at, which are hard corals, because hard corals are pretty actually surprisingly easy to test all this stuff."