Injured Coral Have Less "Sex"

Researchers had previously thought coral rebounded heartily after injuries from hurricanes and boating, but a new study reveals that populations cannot rebuild as quickly as hoped

Join Our Community of Science Lovers!

No one thinks damaging coral is sexy, but researchers from the University at Buffalo just made it official. Turns out, coral sex is dampened after injury from storms and human activity.

Their study shows that while coral adapts to injury events by initially growing back rapidly, reproduction rates are suppressed up to four years after initial injury. This is particularly alarming since size, rather than age, dictates coral's health and maturity, explained study leader Howard Lasker.

Many coral have asexual and sexual reproduction, the latter usually a wild sex party of sorts, where corals release sperm and eggs into the water at a precise time. Those sex gametes hook up with each other, from different individuals, to produce free-floating larvae called planulae.


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


Lasker and his team studied coral colonies in the Bahamas that were being harvested for use in skin care products. They found that even years after harvest spermaries (coral sperm colonies) and polyps, where coral stores eggs, were underproducing.

"On the science side of it, this really raises the question, 'Well, what's going on?'" Lasker told LiveScience. "This is a healthy-looking colony, those wounds [from harvesting] are long, long healed, so what's different about it? And that's something we're still puzzling over."

Christopher Page, Lasker's co-author and now a staff biologist at Mote Marine Laboratory, believes that in the face of a changing environment coral's ability to reallocate resources after injury events shows promising adaptability. [Colorful Creations: Incredible Photos of Coral]

"Coral are more adaptable than we may have thought in the beginning, but that doesn't mean they'll persist despite changes," Page told LiveScience.

When energy is given to one resource — in this case, quick regrowth after injury — it's taken from another, Page explains. This leaves more persistent effects than were previously suspected — in this case, long-term, slowed reproduction.

The findings have implications for future coral health. While researchers had previously thought coral rebounded heartily after injury events, such as those incurred from hurricanes and other storms as well as human activity such as boating, this study reveals that populations cannot rebuild as quickly as hoped. But the most effective way to protect coral continues to be the cessation of injury events altogether.

"When there's damage, that damage has a longer-term effect than we may have initially envisioned, but the more significant factor is that initial damage," said Lasker. Coral is a particularly sensitive creature, affected by a host of climate change-related events from increased water temperature to more frequent and severe storms. And now, research reveals that it is difficult to predict how these marine animals will react to injury, since changing variables will determine their health and growth.

To conserve and protect coral, explained Page, we must both avoid their continued injury, and examine our restoration approaches to consider long-term effects of damage as well as the significant adaptability of these organisms. If a multifaceted and focused approach to management is taken, coral, threatened worldwide, may just be able to revamp its sex life.

Many corals are hermaphroditic broadcast spawners, meaning they release packets of sperm and eggs into the water.

Warming waters signal the coral that it's time to start producing sex cells, then a precise combination of daylight and moonlight trigger the sudden, simultaneous release of eggs and sperm.

Copyright 2012 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe