Northern Red Sea corals live close to the threshold of resistance to cold temperatures

Though these corals can tolerate very high temperatures, a new study reveals that even a slight cold spell can cause bleaching

BAR-ILAN UNIVERSITY

Research News

IMAGE
IMAGE: IN THE NORTHERN RED SEA AND GULF OF AQABA, CORALS HAVE EXCEPTIONALLY HIGH TOLERANCE TO INCREASING SEAWATER TEMPERATURES RESULTING FROM GLOBAL WARMING. HOWEVER, CLIMATE CHANGE WILL ALSO RESULT IN MORE… view more CREDIT: PROF. MAOZ FINE, BAR-ILAN UNIVERSITY

Coral reefs are one of the most biologically diverse ecosystems on earth. In the northern Red Sea and Gulf of Aqaba corals also have exceptionally high tolerance to increasing seawater temperatures, now occurring as a consequence of global warming. This characteristic led coral reef scientists to designate this region as a potential coral reef refuge in the face of climate change – a reef where corals may survive longer than others that are being lost at an alarming rate due to human pressures.

However, global climate change will also result in more variable weather patterns, including extreme cold periods. Some researchers predict that the Red Sea region is entering a cooling phase. Therefore, researchers from Bar-Ilan University and Interuniversity Institute for Marine Science in Eilat conducted an experiment to investigate the effect of an unusually cold winter on corals from the Gulf of Aqaba.

In a paper recently published in the journal PeerJ, they demonstrate that a winter even 1°C cooler than average results in a physiological stress response similar to that seen in other corals under heat stress. This result shows for the first time how perilously close Gulf of Aqaba corals live to their lower temperature threshold.

Previous studies conducted within the research group of Prof. Maoz Fine, of Bar-Ilan University’s Mina and Everard Goodman Faculty of Life Sciences, have used controlled experiments in the Red Sea Simulator System to expose locally abundant corals to increased seawater temperatures expected to occur within and beyond this century. Multiple experiments found that corals from this region have an extraordinary tolerance to high temperatures, which kill corals elsewhere in the world. Prof. Fine’s lab and researchers from other groups have tested multiple coral species and at different phases of their life cycle including the reproductive and larval phases, which are typically more sensitive to environmental change; all show similar tolerance.

“Whilst we have repeatedly demonstrated the high temperature tolerance of corals on the shallow reefs in Eilat, we wanted to test the possibility that this exceptional heat tolerance comes with the trade-off of being cold-sensitive,” said Dr. Jessica Bellworthy, who conducted her doctoral research in Prof. Fine’s lab. “Indeed we found that exposure to cold water periods causes a physiological response akin to bleaching.” Better known as a response to high water temperatures, coral bleaching, is the loss of algal symbionts that must be present within the coral tissue in order to provide the coral with energy. Without the symbionts, the chances of coral mortality are high. Coral bleaching is the leading cause of coral decline in the world today. Therefore, while the corals of the Gulf of Aqaba can tolerate very high temperatures, even an acute cold spell may cause bleaching in this population.

However, Bellworthy and Fine’s cold stressed corals did not die and recovered once water temperatures returned to normal. Experimental corals were maintained at normal temperatures and then underwent a second test – an anomalously hot summer. “It was an important discovery for us to understand that even those individuals that suffered the cold winter stress, still did not bleach at the high temperatures,” says Bellworthy. This is good news for the corals in the Gulf of Aqaba; the high thermal tolerance is not lost and thereby corals should not undergo two bleaching events in the same year, a threat that faces others such as the Great Barrier Reef in Australia.

Coral reefs are highly sensitive to temperature change. Therefore, identifying those that respond differently to thermal stress aids in understanding the mechanisms of environmental adaptation in corals. In addition, researchers can focus attention on conserving and studying such unique reefs.

###

From EurekAlert!

2.3 6 votes
Article Rating
23 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
John Pickens
April 19, 2021 10:23 pm

“Red Sea and Gulf of Aqaba corals also have exceptionally high tolerance to increasing seawater temperatures, now occurring as a consequence of global warming. This characteristic led coral reef scientists to designate this region as a potential coral reef refuge in the face of climate change – a reef where corals may survive longer than others that are being lost at an alarming rate due to human pressures.”

Statements without evidence.
I stopped reading right there.

fred250
Reply to  John Pickens
April 19, 2021 11:01 pm

Obligatory propaganda anti-science BS in the abstract. !

commieBob
Reply to  John Pickens
April 20, 2021 12:41 am

The human pressures that are affecting corals have nothing to do with warming and more to do with pollution and physical destruction. As far as temperature changes go, natural variation swamps even the slight warming we’ve felt since the end of the Little Ice Age.

This graph shows the sea level rise since the last glacial maximum about 20,000 years ago. The oceans used to be 410 feet lower. As far as I can tell, the corals have spent most of the Holocene marching up hill.

Richard (the cynical one)
April 19, 2021 10:27 pm

It’s smart to get on the record that AGW can be the driver of cold weather damage, because then your butt is covered when the icy winds blow in off the advancing glaciers.

Alan the Brit
Reply to  Richard (the cynical one)
April 19, 2021 10:58 pm

Don’t forget, friend, the reason “they” decided to change the language, a’la left-wing reasoning, is to manipulate & control! Can’t remember the exact quote, but it goes something like, “If you control the language, you control the past, when you control the past you can control the present, if you control the present you control the future!”

Steve Case
Reply to  Alan the Brit
April 20, 2021 1:03 am

If you control the language, you control the argument
If you control the argument, you control information
If you control information, you control history
If you control history, you control the past
He who controls the past controls the future.” – Big Brother, 1984

John Tillman
April 19, 2021 10:30 pm

Persian Gulf corals tolerate water temperature down to 14 degrees C, not just the 18.6 degrees in this Gulf of Aqaba study.

https://www.nature.com/articles/srep17639

lee
April 19, 2021 11:07 pm

So how long did they give corals to acclimatise to new conditions?

Rod Evans
April 19, 2021 11:11 pm

I particularly liked this “let’s get this in early” line from the report.
Quote
However, global climate change will also result in more variable weather patterns, including extreme cold periods. Some researchers predict that the Red Sea region is entering a cooling phase.”
The corals that are evidence of variation being normal in living creatures i.e. the Red Sea corals can take the heat but can’t take the cold, (unlike our antipodean coral friends). are at risk from “Climate Change” because it can get cold as well as hot.
All this fear mongering must come to a stop at some point.
Humanity have been singled out as the drivers of Global Warming. Now the facts are in. They show the Planet is in fact simply cyclical in its climate variation. The grant seekers i.e. academic climate researchers, are suggesting we humans are also the cause of climate cooling? Who would have guessed that?
Maybe the climate picture is bigger than human influence in any meaningful way?
Maybe the scale of the global climate system is beyond the average grant seekers capacity to understand it?
It is clearly beyond the capacity of climate modellers to model it.

Philo
Reply to  Rod Evans
April 20, 2021 5:59 am

No maybes about it. The freaks advocating “global warming” do NOT have the evidence to make a case. They can’t even “hindcast” the weather to properly calibrate a model.
Not to mention that few to none of the climate models have anything approaching accuracy in their mechanics.

April 19, 2021 11:27 pm

Most coral thrive best in the warmest water. Even the very warm southern Red Sea is dotted with healthy coral reefs (unlike the cooler Mediterranean). If you look at a map of coral reef locations, you’ll see that they’re clustered around the equator:
 comment image
 
Why do you think that is?
 
Some coral inhabit temperate zones, but most prefer tropics. In fact, where there are seasons, corals grow fastest in summer.
 
At 7:20 in this BBC video you can hear how wonderfully healthy the coral are in warmest part of the very warm southern Red Sea, off Eritrea:
 

Of course the world’s largest coral reef is Australia’s Great Barrier Reef. Contrary to what you might have heard, it is doing fine. It is about 20 million years old, and it has withstood CO2 levels both much higher and much lower, and temperatures both substantially warmer and much colder, and water levels both higher and much lower, than present. We needn’t worry that a degree or two of anthropogenic warming will destroy it. If you want to learn more about the GBR, the go-to experts are Australian Drs. Jennifer Marohasy and Peter Ridd.

H. D. Hoese
Reply to  Dave Burton
April 20, 2021 8:28 am

The famous Gulf of Mexcio Flower Gardens coral (some hermatypic, various classifications) and other reefs (the 2 dots on the map) are submerged 10 fathoms or so at the edge of the continental shelf, 100 miles+ to land depending where you leave from. Not sure if they have been so experimentally studied, but T is close to 20 C year round. They were a delta when sea level was there and are part of the Atlantic experiment to make lionfish extinct.

Currents move larval tropical species all over the GOM, Texas beaches get lots of the flotsam and jetsam from the world. “Satellite data reveals that at any given time surface waters throughout the Gulf are populated by numerous cyclonic and anitcyclonic eddies and rings interacting with one another……..What effect these currents may have on the lives of individual deep-Gulf organisms is not known. What is clear, however, that the currents allow for the transport and dispersal of planktonic pelagic species throughout the Gulf.” from Darnell, 2015. The American Sea: A Natural History of the Gulf of Mexico.

Reply to  H. D. Hoese
April 20, 2021 5:41 pm

Tell me more about the Atlantic experiment to make lionfish extinct!

Oldseadog
April 20, 2021 2:06 am

I notice that they are careful to not specify that they are only talking about tropical corals. There are lots of cold water corals, even here in Scottish waters, but to include them would destroy the loomimg disaster scenario. Being a technodinosaur I can’t give you a link but your search engine will do so for you.

Coeur de Lion
April 20, 2021 2:27 am

Do they mean that global warming causes global cooling? Are we seeing a paradigm shift as the globe ceases to warm? Do we still have to reduce carbon dioxide because it causes cooling? Or should we stop trying to reduce CO2 levels in order to keep us warm? (latest UAH temp= 1988)

Mr.
Reply to  Coeur de Lion
April 20, 2021 8:15 am

Well, the “father of global warming” James Hansen quickly pivoted from telling the media in the 1970s that an ice age was looming, to frightening the children with new stories about how we were frying the atmosphere.

It was all about headlines and funding back then, and nothing has changed since.

Abolition Man
April 20, 2021 5:19 am

These idiots just realized that corals in one of the warmest marine environments on Earth might be sensitive to cold? Ha ha ha ha ha ha!
I wish I could see their explanation for how rising temps caused by the magical molecule are leading to extreme cold! That could be some Olympic class verbal gymnastics!
Maybe they can model when to expect Hell to freeze over!

Philo
Reply to  Abolition Man
April 20, 2021 6:07 am

Wonderful comparison AM.
NONE of the climate modelers or government control freaks seem to understand that we are in the time range for a switch back to the start of a glacial period.
When it does change, and it will no matter what, temperatures will continue to bounce around downward until no one, not even the Russians, will be able to call it global warming.

The change over takes some 1000 or so years so there is no need to panic. But it would not be bad to start looking at how to cope in the future.

Mr.
Reply to  Philo
April 20, 2021 10:27 am

Humans will cope with changed climates in the future just as our ancestors did in the past.

They’ll ADAPT.

(Which is how our species got to the top of the evolutionary tree.
But I do fear from current observations that there are those in our ranks who doing their darndest to take us back to our Neanderthal era. John Kerry has the appearance of one who is already there.)

Jim Clarke
April 20, 2021 3:21 pm

However, global climate change will also result in more variable weather patterns, including extreme cold periods.”

They have been saying things like this for 30 years with zero evidence. On the contrary, reducing the temperature gradient between the poles and the equator would produce less variable weather. That is basic meteorology 101. But man-made climate change has nothing to do with science, does it. The evidence indicates that it is 100% about political power and control.

beng135
April 23, 2021 9:13 am

This characteristic led coral reef scientists to designate this region as a potential coral reef refuge in the face of climate change – a reef where corals may survive longer than others that are being lost at an alarming rate due to human pressures.

Oh good Lord…..

Last edited 3 months ago by beng135
%d bloggers like this: