Climate Change Is Making Sharks Right-Handed

From Live Science

By Brandon Specktor, Senior Writer | December 7, 2018 03:43pm ET


Australian researchers recently bred Port Jackson sharks in a tank warmed to a temperature likely to occur at the end of the century if climate change continues unabated. These warmer waters made the sharks right-handed.

Credit: Shutterstock

Australian scientists went snorkeling for shark eggs, then incubated those eggs in a special tank designed to simulate the hot, end-of-century temperatures expected to prevail if climate change continues unabated. Half of the sharks died within a month. The other half became right-handed.

The team of biologists from Macquarie University in Sydney knew from previous research that warming ocean temperatures alter the way fish grow and develop. The researchers wanted to find out whether these changes would also affect fish behavior — specifically, whether sharks raised in a tank warmed to projected end-of-century temperatures would show a preference for swimming one direction or another when faced with a Y-shaped pathway. Basically, could global warming make sharks right- or left-handed?

Sharks, you may be tempted to point out, don’t actually have hands (they have fins, which are genetically not so far off from human arms). So, when scientists talk about the right or left “handedness” of sharks and other marine creatures, they’re talking about lateralization: the tendency for one half of an animal’s brain to automatically control certain behaviors. With simple, automated behaviors (say, your preference for writing with your right or left hand), this theoretically frees up mental energy for an animal to perform more-complex cognitive functions. In fish, lateralization might mean a default preference for swimming a certain way, which can help those fish forage for food or form schools. [On The Brink: A Gallery of Wild Sharks]

“Since behavioral lateralization is an expression of brain function, it can be used as a barometer of normal brain development and function in some contexts,” the researchers wrote in a study published this summer in the journal Symmetry. “Namely, exposure or development under climate change conditions.”

Right shark or left shark?

To test whether warmer waters could force a shark to become lateralized, the researchers collected a clutch of Port Jackson shark eggs from the waters off of eastern Australia. The scientists incubated 12 eggs in a tank warmed to the current ambient temperature of the bay (about 70 degrees Fahrenheit, or 20.6 degrees Celsius) and 12 others in a tank that was gradually warmed to 74.5 degrees F (23.6 degrees C) to simulate those predicted end-of-century ocean temperatures.

Five sharks incubated in the elevated temperatures died within a month of hatching. To test whether the remaining sharks had developed lateralization, the team placed each of those animals in a long tank with a Y-shaped partition at one end. Behind the partition was a food reward; sharks just had to decide whether to swim to the right or left side of the Y to reach their snack.

The authors found that sharks incubated in the elevated temperatures showed a strong preference for turning right. The sharks in the control group showed no preference one way or the other.

Read the rest of the story here.


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December 9, 2018 2:19 am

Any fines for killing perfectly good sharks to try to prove a nonsense?

Reply to  Gbees
December 9, 2018 7:56 am

The more disappointing part from a science point is they ignore the fact the sharks are in a tank.

Port jackson sharks have a very unusual breathing pattern when resting they only intake water into one gill slit. They also navigate and feed by light polarization as they sit on the bottom as ambush hunters so even having them in a tank is nothing like natural. To race to any conclusion based on tank studies would to any real scientist would be unsafe, but this is climate pseudoscience I guess.

Bill Powers
Reply to  LdB
December 9, 2018 8:31 am

How do we make the unsuspecting majority understand that this is not Science it is Political Science, when they are brainwashed daily through school, Hollywood and the News media that Global Warming is real and it is all their fault?

It has been Political Science from the beginning, ever since the Bureaucrats set up the IPCC, through the UN for the purpose of lending universal credibility, with the mandate to discover an adverse link between man and the environment. This whole charade was born out of Ehrlich’s population bomb that scared the bureaucrats into establishing global jusfification to place the world population under respective national control.

Does anybody believe that the IPCC would come back with a negatory on man made catastrophe with billions of dollars dangling in their face for a positive affirmation? CAGW is a governement created hobgoblin intended to scare the populous into obeisance and obedience to the government by allowing said governments to tax and regulate population control and natural resource usage.

Pseudo-scientists set up their experiments, like sharks in tanks, with the intent of declaring any observable result as evidence of Climate Change and then Surprise, Suprise! The Government uses the rigged science and predetermined, programmed computer modeling to regulate and tax the people. When the government has billions of our dollars to spend they can buy the best scientific results money can buy. Yet they can still only report out that the DOOM AND GLOOM, MIGHT, MAYBE, COULD HAPPEN in pick a number, any number of years just not next year.

Reply to  LdB
December 9, 2018 8:22 pm

They also generate 20 generations worth of climate change in a single generation.

Where’s the evidence that the problem isn’t hatching the eggs in water that is significantly warmer than the eggs were laid in?

December 9, 2018 2:23 am

Sharks raised in warmer water might, with luck, develop such a right-handed tendency that they can only swim in circles like the ‘Bismarck’, cease to be a threat to swimmers and quietly die out.

Reply to  nicholas tesdorf
December 9, 2018 3:51 am

that would be welcome
another poor bugger got chomped off NSW? coast this afternoon,
still alive but critical i think

Don K
Reply to  nicholas tesdorf
December 9, 2018 5:19 am

FWIW Port Jackson sharks (Heterodontus) aren’t man-eaters or even man tasters. They’re typically only 2 or 3 feet long, are sweet tempered (for a shark) and like to have their backs scratched. They are often used in marine parks in “Petting Pools”.

Phillip Bratby
December 9, 2018 2:26 am

What a complete waste of money. The lunatics are truly in charge.

Komrade Kuma
Reply to  Phillip Bratby
December 9, 2018 8:58 am

Australian scientist went snorkelling….. cocaine

Komrade Kuma
December 9, 2018 2:26 am

just where is the line between climate science and caricature?

Paul r
December 9, 2018 2:36 am

So stupid it burns

December 9, 2018 2:41 am

Good grief! Yet another pointless waste of money.

I also read today the mechanism deployed to collect garbage from the ‘Great Pacific Garbage Dump’ doesn’t work, despite spending lots of time and money on it. Of course it worked in theory, before it was actually used. Nor is is simply teething problems, it doesn’t work at the most fundamental level.

Ho Hum.

My enduring belief is that scientists are more often wrong than right otherwise there would be no need for experiments. Why is climate change considered any different and presented as ‘settled science’?

michael hart
Reply to  HotScot
December 9, 2018 5:19 pm

I’ve also read that the Great Pacific Garbage Patch doesn’t really exist. Not meaning that there isn’t a part of the ocean that tends to accumulate more twigs, tree trunks and plastic bottles, but meaning that it just isn’t very noticeable because it’s low density. Thus an observer might travel through it from one side to the other and still wonder when they were going to arrive. A bit like Milton Keynes.

Reply to  michael hart
December 9, 2018 7:54 pm

I’ve often wondered why I’ve never seen a photo of it. Isn’t it supoosed to be bigger than France or Texas or somewhere?

Harrow Sceptic
Reply to  Maverick
December 10, 2018 12:39 pm

No Milton Keynes – a created UK town some 40 miles north of London – is not quite that big. But it most probably seems that large if you are trying to escape from it.

Joel O’Bryan
December 9, 2018 2:58 am

Basic science illiteracy at work with this:
“The scientists incubated 12 eggs in a tank warmed to the current ambient temperature of the bay (about 70 degrees Fahrenheit, or 20.6 degrees Celsius) and 12 others in a tank that was gradually warmed to 74.5 degrees F (23.6 degrees C) to simulate those predicted end-of-century ocean temperatures.”

– So the researchers warmed the tank water at a rate of 0.0325 dec C year^-1 and tested multiple generations along the temp rise to simulate a realistic warming trend in order to account for adaptation?

– So the researchers made the common mistake of confusing surface air temp (SAT) rise projections with 30 meter deep Sea temp rise under climate change?

This is high school level thinking from those supposed researchers.

Reply to  Joel O’Bryan
December 9, 2018 3:32 am

Author Bio

Brandon Specktor, Senior Writer
Brandon Specktor writes about the science of everyday life for Live Science, and previously for Reader’s Digest magazine, where he served as an editor for five years. He grew up in the Sonoran Desert, but believes Sonoran hot dogs are trying way too hard.
(Not meant as an Ad Hom but, seriously?) My emphasis.

The article is followed by comments, I liked this one:

Dominick Mezzapesa
you know what I love about the people who write these stories… they always seems to be so percise on data that promotes their ideas, but always leave out the truth when it does not. This idiot wrote “5 sharks in the elevated temps died the first month…
What he left out was the FACT that two were euthanised because they were not feeding. My emphasis again.

Reply to  Joel O’Bryan
December 9, 2018 4:46 am

Half the sharks died…..the control group was equally divided between left and right
…they killed the left handed sharks

Don K
Reply to  Latitude
December 9, 2018 5:09 am

…they killed the left handed sharks

The bastards!!!

Reply to  Don K
December 9, 2018 10:32 am

They were sinister.

Steve R.
Reply to  Don K
December 10, 2018 4:09 pm

No real mention of experimental control. Perhaps there were other motivations for turning toward the right.

Reply to  Latitude
December 9, 2018 9:19 am

Does this explain why leftists are so afraid of warming?

Reply to  Joel O’Bryan
December 9, 2018 4:57 am

What does sharks (and other spieces) do in nature, when the water is either too warm or too cold? They stay away/migrate. These test subjects was refused that possibility.

Reply to  SasjaL
December 9, 2018 1:07 pm

Exactly. Or they adapt in other ways – like go deeper, find shade, etc. A generally unknown fact: the oceans are fairly large, and even more surprising, somewhat deep. Hence the phrase “My love is deeper than an ocean.” You rarely hear someone say “My love is deeper than my aquarium.”

Hocus Locus
Reply to  Joel O’Bryan
December 9, 2018 5:52 am

Why not boil the eggs? We could have this study knocked off in a week.

December 9, 2018 3:07 am

I’m currently working on a study looking at the left minded thinking of people as the Co2 increases and there seems to be a strong correlation.

a right-minded lefty
Reply to  Robertfromoz
December 9, 2018 5:35 am


Rich Davis
Reply to  Robertfromoz
December 9, 2018 6:24 am

You forgot to say, “Much more money is needed for research”

Reply to  Rich Davis
December 9, 2018 9:34 am

But the scientists didn’t read the whole article and they say very clearly a lot more research is needed.

December 9, 2018 3:30 am

I am embarrassed to be an Australian right now

Reply to  Crakar24
December 9, 2018 3:58 am

embarrassed yes
and also angry!
wonder how much taxfunds went into this crud?
and who approved it
the recent stink over refusals for funding for utterly daft requests to study some obscure tripe in Malta got the headlines, and good ol auntys staff all moaning how the “yarts” and “culshure” needs to be nurtured.
well no, they dont . more funding refusals for tripe like this as well would be smart

John of Cloverdale, Western Australia
December 9, 2018 3:30 am

It so appears, that further up the coast, Global Warming is making sharks hungry.

December 9, 2018 3:41 am

Research finds Republican voting sharks much friendlier than their Democratic voting cousins.

December 9, 2018 3:59 am

Would it be very wrong of me to wish we could send all “climate scientists” snorkelling with sharks, preferably very large, very hungry white pointers, the type that has been attacking a lot of people around Oz recently.

Reply to  Hasbeen
December 9, 2018 5:02 am

Just drop them off in the Chesapeake Basin during the mating season and see how long they last. A diving friend of mine told me that sharks seem to gather there to mate by the hundreds. I’m sure those big ol’ finsters get hungry after a mating session. 🙂
[Ba-dum… ba-dum… dudududududududu!] (Sorry, could not resist.)

Reply to  Sara
December 9, 2018 1:09 pm

Well done, Sara? I could hear the music!

December 9, 2018 4:09 am

“Australian researchers recently bred Port Jackson sharks in a tank warmed to a temperature likely to occur at the end of the century if climate change continues unabated”

… and there was me thinking that if something is changing (e.g. Climate) it does not remain the same, nor does it continue in the same direction hence the word “change”
Change does not normally mean “remains the same” nor “continues in the same direction”.

Of course they might be referring to word by “change” as used by scienastrologers

December 9, 2018 4:33 am

Perphaps a Carcharodon Abidexdrodon will evolve?

I will get my coat.

December 9, 2018 4:36 am

Perphaps a Carcharodon Abidexdrodon will emerge?

I will get my coat.

Reply to  Julian
December 9, 2018 4:48 am

Duplicated comment deleted.

Reply to  Julian
December 9, 2018 12:52 pm

Julian is getting two coats.
Must be cold.
CAGW is therefore potentially totally wrong.
Please send more grant money – I need to check this, personally, with hundreds of other folk in Hawaii, the Bahamas, nice parts of Australia and New Zealand, and several good French vineyards.

Thanks in advance.

December 9, 2018 5:02 am

I suggest the scientist apply for more funds to study if the same applies to sharks in the northern hemisphere or if they contra rotate. They also need to study if the orientation of the tank at various compass points alters their behavior, of the sharks that is.

Rich Davis
Reply to  kalsel3294
December 9, 2018 6:30 am

Yes, much, MUCH more money is needed!

December 9, 2018 6:05 am

Sharks survived 450 million years of natural climate change, but perturbed by 150 years of natural climate change possibly slightly augmented by man. Sounds entirely plausible and needs worrying about – now where is that crack pipe.

HD Hoese
December 9, 2018 6:57 am

First line of conclusions—
“In this study, we showed that incubation the temperatures predicted for the end of the century affect behavioral lateralisation in Port Jackson sharks.”

Two days ago I was talking with someone who had done a great deal of good research on the early stages of red drum, the redfish of “blackened” fame. His current study produced eight data points. I remarked as to how interesting that was and asked if there was an outlier. He said no, but eight is far from being able to draw any conclusions with certainty.

A non-blackened redfish was once found in the stomach of a great white shark. Conclude what you want about temperatures, so far in red drum land it might now be cool enough to occur again.

“Five sharks from the elevated temperature treatment did not survive the first month after hatching (three deaths and two were euthanised because they were not feeding).” “42% of sharks reared in elevated temperatures died prior to testing.” While there may be something to ‘handedness’ in sharks I would suggest that they first learn the difficult task as how to keep sharks alive. Because important things can come from small samples, this might be worth a very short note, if they first learn about hypothesis testing.

This is the first and only paper I ever read in the journal Symmetry.

Michael Darby
December 9, 2018 7:14 am

Very likely Australian taxpayers paid for this rubbish. Nobody thought to compare the casualty rate of baby sharks incubated in unheated water since this was a political experiment rather than a scientific experiment. of some slight relevance is this non-exhaustive list of entities established or supported by the Australian Government in its craven enthusiasm for the global warming cult:
• the Clean Energy Finance Corporation
• the Emissions Reduction Fund
• the Clean Energy Innovation Fund (
• the Renewable Energy Target
• the Carbon Neutral Program
• the Solar Communities Program
• the National Greenhouse and Energy Reporting Scheme (NGERS)
• Hydrogen Energy Supply Chain Pilot Project
• the National Greenhouse Gas Inventory Program
• the Australian Renewable Energy Agency (ARENA)
• the Carbon Capture and Storage Research Development and Demonstration Fund
• the Equipment Energy Efficiency (E3) Program
• the National Low Emissions Coal Initiative
• Carbon Farming Futures
• the Australian Renewable Energy Mapping Infrastructure project.
• the United Nations Framework Convention on Climate Change
• the Asia-Pacific Rainforest partnership
• the Mission Innovation Initiative
• the International Partnership for Blue Carbon
• The Green Vehicle Guide and Truck Buyers Guide
• Fuel efficiency and CO2 labelling
• the Intergovernmental Panel on Climate Change (IPCC)
• Coast Adapt
If anyone works out the annual cost to Australian taxpayers, please advise me at and I shall be deeply grateful

December 9, 2018 7:28 am

So Katy Perry is the brilliant one?

Tom in Florida
December 9, 2018 8:39 am

The Coriolis Effect?

December 9, 2018 8:43 am

At first I thought it was a made-up story to parody some of the weird studies coming out these days!

Steve Reddish
December 9, 2018 8:57 am

I have two issues with this study:

1) The 5 sharks in the warmer tank displayed a “strong” preference for turning right, but they don’t give out the numbers. Is that because the ratio was 3 right and 2 left, and they don’t want us to realize 5 can’t be divided any closer to 50%? Far too small of a sample size.

2) they say:
” “Elevated temperature significantly increased developmental rates and metabolism, with associated costs in terms of energy allocation to growth and physiological processes,” the researchers wrote. “Therefore, stronger lateralization may arise as an energy-saving mechanism.”

Sharks born in hotter waters may be forced to develop more quickly and may be left with physically smaller brains than sharks who develop under today’s conditions, the team wrote. With less mental energy to spare, sharks might have to automate certain behaviors — like always turning right when faced with an obstacle.”

So, sharks grow faster in warmer water and thus they might have had to allocate their food resources differently than normal. What? Did somebody forget to feed those sharks extra after seeing their higher growth rate? Wouldn’t sharks in the wild have eaten more if they needed to?

I counted 3 “may” and 1 “Might” in their statement of conclusions. Pure speculation. Did they measure the brain sizes of all the sharks, or are they guessing?


Steve Reddish
Reply to  Steve Reddish
December 9, 2018 9:05 am

Make that 4 “may” and 1 “might”


December 9, 2018 9:12 am

Many taxpayers WERE harmed by this brain dead waste of a “study”.

Hoyt Clagwell
December 9, 2018 9:35 am

I just want to know how they would determine whether this “left handedness” was a detriment or an improvement. Especially for sharks that live in an ocean that has no such channels with forking decisions to be made.

Crispin in Waterloo
December 9, 2018 12:44 pm

Is it possible that a mommy shark could swim to a cooler place? Are they self-aware enough to know they can swim?

December 9, 2018 1:02 pm

What species of shark is that in the photo? Anyone know? Shutterstock did not identify it.

Reply to  Sara
December 9, 2018 10:13 pm

It is an Australian Port Jackson Shark (Heterodontus portusjacksoni) — Port Jackson is the official name of Sydney Harbour. It is a migratory species, traveling south in the summer and returning north into warmer waters to breed in the winter. As you can see by its mouth structure, it feeds mainly on hard-shelled molluscs, crustaceans, sea urchins, plus some fish. It is not a killer and can be tamed in captivity.

Anyone with more than 2 brain cells might think that being migratory, it could easily select a water temperature suitable to nurture itself and its offspring.

December 9, 2018 1:07 pm

Sharks have hands?

Reply to  DonK31
December 9, 2018 3:03 pm

Sharks are the worst kind of pickpockets, pilferers and car burglars. There used to be a sign in the Tomales Point trailhead car-park at the Point Reyes National Seashore that read “Warning: Great White Shark area. Do not leave valuables in your car.”

December 9, 2018 1:48 pm

So did the sharks become “right-handed” and die when temperatures were much warmer in the past. If not, why not? I’m calling BS on this story.

December 9, 2018 2:45 pm

I remain curious still, what does a sharks “hand” look like?

Tom in Florida
Reply to  getitright
December 10, 2018 8:44 am

5 Aces.

December 9, 2018 3:13 pm

Those who even thought up this crap should be thrown behind bars for 1, molesting wildlife, 2 trying to convince people that this shit is serious and 3, just because it will make me feel better.

Craig from Oz
December 9, 2018 4:49 pm


if I understand this correctly, they had 12 sharks in the hot tank and 5 were ‘unable to continue’ to testing. This left 7 which then showed a ‘strong preference’ to turning right. Which is? 7 out of 7? 6 out 7? 5?

Assuming they have set up their tests correctly the left/right test should be 50/50. Assuming. Anyone ever studied fully the factors that affect a shark tank?

However, with only 7 sharks and a basic 50/50 getting all 7 to go Right is not that unusual. Unlikely, but I would like to see someone who understands probability more demonstrate this is not just noise.

So, assuming this isn’t just noise, let us look at one of the conclusions: hotter water forces sharks to develop an energy saving method.

Sorry, but what? You conclude that from ONE generation and a sample size of 7? Yeah… of course…

Then, if you are still playing at home, comes the realisation that the purpose of this research was to determine if sharks were left or right handed and then cook them to see if they could modify this. This was their end game. This, apparently, is what Climate Research is all about.

However there is one important fact these ‘researchers’ failed to comment on that is perhaps the most important observation of them all.

Sharks will survive in warmer waters!

True some of them died, but the point is that some of them didn’t. They will survive. 3 degs C will not instantly kill off sharks, so the 2 deg screamed by the IPCC is clearly also not a threat.

Warming seas? Nothing to worry about. This research has shown that.

December 9, 2018 5:34 pm

How well did they control the currents and eddies in the pool?
Sharks are extremely sensitive to finding food – A shark can sniff out fish extracts that make up only one part for every 10 billion parts [source: Elasmodiver] .
Were those who performed the experiment able to measure the concentration of the smell of the food to within 1/10,000,000,000 at all points in the tank to assure that the right and left paths both had the exact number of molecules of the food throughout the water path?
If not, then it isn’t a valid study.

Also, if one is to assume it is a valid study, since humans tend to exhibit a strong tendency toward right-handedness, does that mean that humans are “left with physically smaller brains than other animals” and “have less mental energy to spare?”

Critical Mass
December 9, 2018 7:30 pm

The sharks were Marxist. They wanted to end up on the right side of history. Which is why they ended up going around in circles.

December 9, 2018 8:39 pm

Out of interest, has anybody calculated the amount of energy required to raise the surface water temp in Port Jackson (and presumably entire Pacific) by 3C?

Wiliam Haas
December 10, 2018 1:46 am

I did not realize that sharks had right hands.

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