Quantcast

Ocean Heat Waves Kill Coral Instantly, Study Finds

Oceans
Lizard Island, Great Barrier Reef. The Ocean Agency / Xl Catlin Seaview Survey

Marine heat waves are increasing in frequency, duration and intensity, which spell trouble for corals, according to new research from scientists working at the Great Barrier Reef.


The increased frequency in heat waves is a direct byproduct of the climate crisis the scientists say, as the BBC reported.

The researchers knew that oceanic heat waves contributed to coral degradation, or bleaching, where the coral sheds the colorful algae covering and nourishing it and the coral slowly starves. What surprised the scientists was just how rapidly they died off when they experience a heat wave, according to Agence France Presse.

Yet, while corals can often regenerate after a bleaching event once ocean temperatures are more hospitable to the corals' symbiotic algae, heat waves that come on rapidly and linger are separate existential event that cause immediate death. Reefs will also have to weather extreme marine heat waves, which is "a distinct biological phenomenon from bleaching events," according to the study's authors, led by William Leggat, a coral reef expert at the University of Newcastle in Australia, as Vice's Motherboard reported.

"Now, we see there is also a temperature at which the coral animal itself suffers from heat-induced mortality," explained co-author Tracy Ainsworth, a marine biologist at the University of New South Wales, in an email, as reported by Vice. "This isn't starvation, this is the animal itself undergoing mortality directly from the heat of the water."

To perform the study, the researchers looked at two coral species that were severely affected by a 2016 marine heatwave that struck Australia's Great Barrier Reef and resulted in 90 percent of the reef experiencing some degree of bleaching, according to Vice.

In laboratory conditions, the researchers exposed the corals to simulations of the extreme and rapid temperature increases experienced by the reefs suffering a marine heat wave. They saw that it did not kill the reef slowly, instead the corals lose their tissues, which exposes their skeleton to microbes that dissolve them.

Essentially, in a sever heat wave, a whole structure of a coral colony collapses, as Vice reported.

"The scary thing is — this is a new phenomenon that's being caused by climate change," said Leggat to the BBC. "And the impacts are even more severe than we had thought."

"Climate scientists talk about 'unknown unknowns' — impacts that we haven't anticipated from existing knowledge and experience," said James Heron, a scientist at James Cook University who contributed to the study, as Agence France Presse reported. "This discovery fits into this category. As we begin now to understand this impact, the question is how many more of these 'unknown unknowns' might there still be that could bring faster and greater damage to coral reefs from climate change."

Scientists hope that politicians and policy makers will start to pay attention to the climate science and recognize the need for urgent action to protect the Great Barrier Reef.

"It's hard to know just how much we have to keep saying that this is a big problem before policy-makers decide to do something about it," said Dr James Guest from Newcastle University in the UK, who has been studying coral reef habitats for more than 15 years and was not involved in the study, as the BBC reported.

EcoWatch Daily Newsletter

A mural in Richwood, West Virginia, a once booming Appalachia coal town, honors the community's history. Jeff Greenberg / Universal Images Group / Getty Images

By Jeff Turrentine

The coal industry is dying. But we can't allow the communities that have been dependent on coal to die along with it.

Read More Show Less
ThitareeSarmkasat / iStock / Getty Images

by Jillian Kubala, MS, RD

Every fruit lover has their go-to favorites. Bananas, apples, and melons are popular choices worldwide and can be purchased almost anywhere.

Read More Show Less
Sponsored
belchonock / iStock / Getty Images Plus

By Hrefna Palsdottir, MS

Coconut oil is an incredibly healthy fat.

Read More Show Less
Wesley Martinez Da Costa / EyeEm / Getty Images

By David R. Montgomery

Would it sound too good to be true if I was to say that there was a simple, profitable and underused agricultural method to help feed everybody, cool the planet, and revitalize rural America? I used to think so, until I started visiting farmers who are restoring fertility to their land, stashing a lot of carbon in their soil, and returning healthy profitability to family farms. Now I've come to see how restoring soil health would prove as good for farmers and rural economies as it would for the environment.

Read More Show Less
skaman306 / Moment / Getty Images

By Jillian Kubala, MS, RD

Radish (Raphanus sativus) is a cruciferous vegetable that originated in Asia and Europe (1Trusted Source).

Read More Show Less
Sponsored
Tinnakorn Jorruang / iStock / Getty Images

By Dan Nosowitz

The budding research on cannabidiol, or CBD, attracts a great deal of interest in the agricultural field.

Read More Show Less
Oksana Khodakovskaia / iStock / Getty Images

By Jillian Kubala, MS, RD

The loquat (Eriobotrya japonica) is a tree native to China that's prized for its sweet, citrus-like fruit.

Read More Show Less

The Centers for Disease Control (CDC) released new numbers that show vaping-related lung illnesses are continuing to grow across the country, as the number of fatalities has climbed to 33 and hospitalizations have reached 1,479 cases, according to a CDC update.

Read More Show Less