From Yale University: Fish of Antarctica threatened by climate change
A Yale-led study of the evolutionary history of Antarctic fish and their “anti-freeze” proteins illustrates how tens of millions of years ago a lineage of fish adapted to newly formed polar conditions – and how today they are endangered by a rapid rise in ocean temperatures.
“A rise of 2 degrees centigrade of water temperature will likely have a devastating impact on this Antarctic fish lineage, which is so well adapted to water at freezing temperatures,” said Thomas Near, associate professor of ecology and evolutionary biology and lead author of the study published online the week of Feb. 13 in the Proceedings of the National Academy of Sciences.
The successful origin and diversification into 100 species of fish, collectively called notothenioids, is a textbook case of how evolution operates. A period of rapid cooling led to mass extinction of fish acclimated to a warmer Southern Ocean. The acquisition of so-called antifreeze glycoproteins enabled notothenioids to survive in seas with frigid temperatures. As they adapted to vacant ecological niches, new species of notothenioids arose and contributed to the rich biodiversity of marine life found today in the waters of Antarctica.
Notothenioids account for the bulk of the fish diversity and are a major food source for larger predators, including penguins, toothed whales, and seals. Yale’s Peabody Museum of Natural History has one of the most important collections of these specimens in the world.
However, the new study suggests the acquisition of the antifreeze glycoproteins 22 to 42 million years ago was not the only reason for the successful adaptation of the Antarctic notothenioids. The largest radiation of notothenioid fish species into new habitats occurred at least 10 million years after the first appearance of glycoproteins, the study found.
“The evolution of antifreeze was often thought of as a ‘smoking gun,’ triggering the diversification of these fishes, but we found evidence that this adaptive radiation is not linked to a single trait, but to a combination of factors,” Near said.
This evolutionary success story is threatened by climate change that has made the Southern Ocean around Antarctica one of the fastest-warming regions on Earth. The same traits that enabled the fish to survive and thrive on a cooling earth make them particularly susceptible to a warming one, notes Near.
“Given their strong polar adaptations and their inability to acclimate to warmer water temperatures, climate change could devastate this most interesting lineage of fish with a unique evolutionary history,” Near said.
Yale-affliated authors of the study are Alex Dornburg, Kristen L. Kuhn, and Jillian N. Pennington.
===============================================================
I have to wonder though, what warming/climate change in Antarctica?
Maybe they are thinking of the surface record on the peninsula, where the greatest concentration of research stations, people, and energy use is. The air temperature there shows an increase.
But sea temperature near the peninsula doesn’t seem to be on the rise:
Or maybe they’ve spent too much time looking at Eric Steig’s graph:
Real Climate’s Dr. Eric Steig’s version, 2009 – from the cover of Nature
Instead of the one from 2004 before the Mannian PCA team math was applied to it:
Of course we now know thanks to O’Donnell et al that the whole “Antarctica is warming” theme from Steig and the team was just another statistical fabrication of air temperature.
Condon and O”Donnell’s Antarctic temperature profile, 2010.
It seems all the warming is in the peninsula, in the air temperature record, where all the people and energy use to keep them warm is.
Antarctica as a whole is not warming much at the surface, and as the UAH lower troposphere graph shows, not at all above the surface.
Antarctic sea ice seems to agree, it has an upward trend:
Joshua Corning makes an excellent point in comments:
“tens of millions of years ago a lineage of fish adapted to newly formed polar conditions”
“A rise of 2 degrees centigrade of water temperature will likely have a devastating impact on this Antarctic fish lineage”
That is weird…one wonders how they survived the far greater temperature changes over the past 20 million years.
You know…when Antarctica melted then froze gain….(image from Wikipedia)
Jeff Alberts
February 14, 2012 at 8:20 pm
The cinematography is amazing. Watch it with the sound off, you’ll be glad you did.
###
I wish I had. It never thought to turn the sound off. The visuals were absolutely stunning, that was why I bothered to watch it. I guess the BBC was counting on the visuals distracting from the insidious lies of the narration, beautifully colored and sweet tasting pills of poison.
Fifty years ago academics believed “Darwin’s Theory of Evolution of the Species”. Now they would never admit they believed it or that it existed.
The current theory is ‘Welfare of the Species”. All species are wards of the state or UN and are incapable adaptation or survival without the protection of well paid government biologists.
Ten years from now nobody will admit that they believed in AGW.
Pat Moffitt
February 14, 2012 at 7:51 pm
###
I did some more reading about how this family partitions its habitat. The rapid specification makes a lot more sense to me now.
As for Pomatomus saltatrix, what a magnificent animal! I can just image seeing it feed. I once ended up with a couple of Salminus brasiliensis. They have a similar body plan. I had them in a 2000 L tank. Watching these guys was an experience. They were not like a lot of piscivores, that just hang quiet. I seem to remember that each species of Salminus inhabits a different drainage system in South America, and is found throughout that system, kind of like Ptychocheilus in the SW US.
Alternatively, if the Seven Big Predictions of AGW have come true by the end of the next solar cycle, few folks will admit they disbelieved it.
The point being, that rational skepticism has to allow for both possibilities.
The genes for the anti-freeze proteins obviously existed as recessive alleles long before the most ice-age started. Functional coding genes just don’t appear and disappear as rapidly as the alarmists would have you believe. They get switched on and switched off as needed. Destruction takes millions of years of being switched off. Random mutations in genes that aren’t essential for survival can accumulate until after millions of years no copies are left that have any hope of working if switched back on again. If we were to somehow restore the poles to the temperate zones they normally are it would be a very long time before all the anti-freeze genes got wiped out of the global gene pool. This is such a non-worrisome thing it boggles the mind that it’s worth the bandwidth it takes to distribute it in electronic form.
In the day when big enviro was working to shut down the logging industry in the northwest US, they found some schill to claim that the spotted owl was going to be driven to extinction by logging because they could only live in old growth forests. It was all peer reviewed.
The logging was stopped. Then it was discovered that spotted owls were perfectly able to adapt to new growth and even urban landscapes.
This report on the fish is misleading in so many ways as to make even spotted owl liars blush.
Or anti-freeze sugar like glucose.
To what degree? There exists a point in time where it is no longer dawn and you can actually see the edge of the sun coming up in the east. When I can finally see it I cease to be a rational skeptic that the sun exists and become a believer.
The only daylight I can see is that there remains zero correlation to suggest that CO2 has ever had any detectable affect on global temperature. Without that all the rest is a window dressing allowing for an endless stream of rationalized excuses by alarmists.
I don’t like to be “picky” but ..I will
“A rise of 2 degrees centigrade ……………….said Thomas Near, associate professor……………………..”
2 degrees celsius not 2 degrees of a protractor.
I would stop reading the pape/article at that point.
(Apologies if this has already been mentioned earlier in this thread. Certainly drawn much comment.)
“”””” Ian H says:
February 14, 2012 at 8:43 am
Ian H says:
Not much chance of an urban heat island effect going on there I’d say.
ferd berple says:
On the contrary, where do you think the temperature recording stations are located? Are they located near the settlements so that they can be serviced, or are they located hundreds of miles away? Are they serviced by reptiles or warm-blooded creatures using fossil fuel based machinery kept considerably warmed than ambient temperatures?
These are science stations – places whose very reason for being is science – staffed by scientists who are not fools. These are not neglected poorly thermometers at an airport. I really doubt that these thermometers are poorly sited. “””””
Well Ian, I have to disagree with you. It is an absolute certainty that these thermometers are poorly sited, and anyone who can read a map can see that for themselves.
If you look at a south polar view map of Antarctica, it is obvious that the Antarctic peninsular points northwards to a place that clearly lies outside the Antarctic circle, where it juts out into the warm waters of the Southern ocean, which slosh back and forth from the Pacific to the Atlantic twice a day.
So if they don’t want to measure such high Temperatures, they need to move these thermometers off the Antarctic peninsula, and move them further south where they will be colder.
So it IS a siting problem; they put those thermometers in a warm place.
DesertYote says:
“100 species??? Thats a lie. Their are only 50 species in 8 genera in Nototheniidae. I don’t have time to research, but I would put money down that the only reason that the count is so high is because of splitters”
That is because you are a bozo. Yes, you did not have time to research, which is why you did not realize that “Nototheniidae” is one group classified in Notothenioidei, along with Artedidraconidae, Bathydraconidae, Channichthyidae, and Harpagiferidae. It is not a lie, it is an illustration of an uneducated boob talking about something of which they know very little
James Worldisgettingwarmer says:
February 16, 2012 at 5:16 pm
Put your blog name anongside this temperature history and its clear who’s the bozo.
The evolution of “antifreeze” is just one more step toward cold adaptation. Before that was the abandoning of hemoglobin. When the polar caps do disappear these fish will go extinct. They would have a hard time competing with fish that have retained their hemoglobin–they would have to evolve it all over again. Not gonna happen. But then the big melt isn’t gonna happen either, not very soon anyway.
But the claim that the former warm water fish went extinct 30mya doesn’t make much sense either–they should have simply headed for warmer waters. –AGF
Absolute bullshit, antifreeze doesn’t explode the moment the temp passes 0°F.
Breed them in captivity and then see if they can adapt – do SCIENCE before you publish findings.
prjindigo says:
February 18, 2012 at 12:15 am
=======================================================
If prjindigo ever returns to this thread it will be his lucky day–he will learn more about it in 2 minutes than he has in his previous life time.
It’s not about whether these fish can survive in a warm aquarium, or at some particular temperature above freezing. I don’t doubt they can survive water warmer than what they currently thrive in. The fact is, they are temperature specialists. They are very highly specialized. They can live in water that few other fish can survive in. They can compete successfully in very cold water. But put them in warm water and they have to compete with all the other fish. Can they swim faster? No, for starters they have no hemoglobin, which makes for a low metabolism. They’ll be some of the slowest fish in the water.
See, your body temperature approximately preserves the temperature of the the Devonian waters in which your vertebrate physiology evolved. Your ancestors evolved hemoglobin, a cardiovascular system, lungs, a four-chambered heart, blood cells with no nucei, and so on, just so you could compete with other critters with high metabolism. In Devonian times most fish had lungs. But amphibians came along, and then reptiles, and they evolved higher metabolisms still, and when the reptiles returned to the seas they made the lungfish go extinct. Lungfish only survived in tropical rivers, and the amphibians only survived in fresh water. They survived by dropping out of competition with the top of the line predators. They reverted to breathing through their skin, and some lost their lungs altogether.
All the so called cold blooded animals have likewise reverted to low energy niches, finding safety in isolation and inactivity. The fish that survived generally took to deeper water–they could not compete with birds. The teleost lung was converted to a swim bladder. The coelecanth lung atrophied as it permanently abandoned surface waters. The ancestors of crocodiles were active, agile predators. Snakes and lizards are in no way representative of their ferocious ancestors, as far as their metabolic behavior is concerned.
But there was a niche available for cold water fish in fast moving streams with lots of dissolved oxygen, once teleosts had evolved a cold physiology. Hemoglobin doesn’t work at temperatures slightly above freezing. That’s why your cheeks turn red in the cold. So some fish abandoned the metabolism shared by trout and salmon and took to waters too cold even for them. Turn up the heat a little and the salmon will move in. Then that antifreeze will do them no good at all, and they’ll be food for faster fish. They evolved in arctic conditions. Remove those conditions and they will go extinct. No question about it.
If humans ever brought about such severe climate change it would be possible to keep these species alive in cold aquariums. We’ll worry about that when the sea rises more than 10 inches per century. –AGF