Basic premise of this paper: 1. let’s take fish out of their natural ocean environment, 2. put ’em in a tank where they are stressed, 3. crank up the temperature, 4. see if any fish die, 5. count dead fish, 6. assume natural adaptation is impossible 7. report news of future doom to the world via press release.
Via Eurekalert:
According to an international team of researchers, the rapid pace of climate change is threatening the future presence of fish near the equator. “Our studies found that one species of fish could not even survive in water just three degrees Celsius warmer than what it lives in now,” says the lead author of the study, Dr Jodie Rummer from the ARC Centre of Excellence for Coral Reef Studies at James Cook University.
Dr Rummer and her colleagues studied six common species of fish living on coral reefs near the equator. She says many species in this region only experience a very narrow range of temperatures over their entire lives, and so are likely adapted to perform best at those temperatures.
This means climate change places equatorial marine species most at risk, as oceans are projected to warm by two to three degrees Celsius by the end of this century.
“Such an increase in warming leads to a loss of performance,” Dr Rummer explains. “Already, we found four species of fish are living at or above the temperatures at which they function best.”
The team measured the rates at which fish use oxygen, the fuel for metabolism, across different temperatures – at rest and during maximal performance. According to the results, at warmer temperatures fish lose scope for performance. In the wild, this would limit activities crucial to survival, such as evading predators, finding food, and generating sufficient energy to breed.
Because many of the Earth’s equatorial populations are now living close to their thermal limits, there are dire consequences ahead if these fish cannot adapt to the pace at which oceans are warming.
Dr Rummer suggests there will be declines in fish populations as species may move away from the equator to find refuge in areas with more forgiving temperatures.
“This will have a substantial impact on the human societies that depend on these fish,” she says.
A concentration of developing countries lies in the equatorial zone, where fish are crucial to the livelihoods and survival of millions of people, including those in Papua New Guinea and Indonesia.
In an era of rapid climate change, understanding the link between an organism and its environment is crucial to developing management strategies for the conservation of marine biodiversity and the sustainable use of marine fisheries.
“This is particularly urgent when considering food security for human communities.”
‘Life on the edge: thermal optima for aerobic scope of equatorial reef fishes are close to current day temperatures’ by Jodie Rummer, Christine Couturier, Jonathan Stecyk, Naomi Gardiner, Jeff Kinch, Goran Nilsson and Philip Munday, appears in Global Change Biology.
Abstract
Equatorial populations of marine species are predicted to be most impacted by global warming because they could be adapted to a narrow range of temperatures in their local environment. We investigated the thermal range at which aerobic metabolic performance is optimum in equatorial populations of coral reef fish in northern Papua New Guinea. Four species of damselfishes and two species of cardinal fishes were held for 14 days at 29, 31, 33, and 34 °C, which incorporated their existing thermal range (29–31 °C) as well as projected increases in ocean surface temperatures of up to 3 °C by the end of this century. Resting and maximum oxygen consumption rates were measured for each species at each temperature and used to calculate the thermal reaction norm of aerobic scope. Our results indicate that one of the six species, Chromis atripectoralis, is already living above its thermal optimum of 29 °C. The other five species appeared to be living close to their thermal optima (ca. 31 °C). Aerobic scope was significantly reduced in all species, and approached zero for two species at 3 °C above current-day temperatures. One species was unable to survive even short-term exposure to 34 °C. Our results indicate that low-latitude reef fish populations are living close to their thermal optima and may be more sensitive to ocean warming than higher-latitude populations. Even relatively small temperature increases (2–3 °C) could result in population declines and potentially redistribution of equatorial species to higher latitudes if adaptation cannot keep pace.
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UPDATE: from comments –
Even relatively small temperature increases (2–3 °C) could result in population declines and potentially redistribution of equatorial species to higher latitudes if adaptation cannot keep pace.
But what’s this I see? Acclimatization of the damselfish mentioned above! Good grief, we can’t have this.
Abstract – 2013
Evidence for developmental thermal acclimation in the damselfish, Pomacentrus moluccensis
Tropical species are predicted to have limited capacity for acclimation to global warming. This study investigated the potential for developmental thermal acclimation by the tropical damselfish Pomacentrus moluccensis to ocean temperatures predicted to occur over the next 50–100 years. Newly settled juveniles were reared for 4 months in four temperature treatments, consisting of the current-day summer average (28.5 °C) and up to 3 °C above the average (29.5, 30.5 and 31.5 °C). Resting metabolic rate (RMR) of fish reared at 29.5 and 31.5 °C was significantly higher than the control group reared at 28.5 °C. In contrast, RMR of fish reared at 30.5 °C was not significantly different from the control group, indicating these fish had acclimated to their rearing temperature. Furthermore, fish that developed in 30.5 and 31.5 °C exhibited an enhanced ability to deal with acute temperature increases. These findings illustrate that developmental acclimation may help coral reef fish cope with warming ocean temperatures.
Couldn’t dem fishies just swim to cooler water?
A self-named Center of Excellence. Indeed.
Is there any evidence that tropical oceans are going to warm?
First off the tropics are predicted by the models to warm the least.
Secondly, as water warms, evaporation increases rapidly.
There’s one problem with all this…since the 1998 El Nino, equatorial Pacific temperatures have never exceeded that high, in fact, they’ve somewhat cooled off with a La Nina bias ever since. I remember keeping a fish tank at 27C, except when I went on vacation when w/o aircon, the water temp zoomed up to 34C…not a single fish died, even when that went on for 3 weeks straight…
…BUT I DO RECALL PLENTY OF TROPICAL FISH DYING OF COLD WATER TERMPERATURES IN BRAZIL, THE CARIBBEAN, ETC… or do tropical fish deaths due to cold water leave the global warmists cold (if you’ll excuse the pun).
I don’t know under what condition their test could ever be duplicated in the real world. I suppose molten lava may increase nearby ocean temps that quickly, but I’m at a loss on how the oceans can increase their heat content so quickly in only a two week period.
This appears to be a very foolish and wasteful study.
“Chromis atripectoralis, is already living above its thermal optimum of 29 °C.”
Are they claiming that in recent history, the tropical oceans were 2C cooler?
I’m confused – I thought the ocean depths were warming, suppressing surface warming and causing the “pause”. So where is the 3c of upper ocean heating supposed to come from?
I’ve never been prouder to call myself a scientist.
No. What the study actually found was that, given virtually no time to adapt to changing conditions, certain fish were … wait for it … unable to adapt.
I think we have a candidate for the igNoble prize here.
My experience with tropical fish at home has taught me that the rate of temperature change is a lot more important than the absolute temperature – when talking about a few degrees up or down.
“Our studies found that one species of fish could not even survive in water just three degrees Celsius warmer than what it lives in now”
The thermal mass of the oceans is immense. Is a 3 degree increase even remotely realistic?
And we get 7 more years of this crap. Gee thanks Australian politicians.
http://www.coralcoe.org.au/news/breaking-news-coral-centre-awarded-7-years-of-funding
Given the craziness, should that university perhaps be re-named John Cook University?
As any fisherman knows, fish will live in substantially different water temperatures but must have time to adapt to the varying temperatures. Here is a quote on black bass showing the range of adaptable temperatures.
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Largemouth bass inhabit lakes, reservoirs, ponds, and medium to large rivers primarily, yet because they are so adaptable they can also thrive in ditches, creeks, canals, and sloughs. Their adaptability is due in large part to the large temperature range in which they can live, which extends to waters above 90 F down through the mid-30s F. The ideal temperature for largemouth bass is between 65 and 85 F.
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The Stupid…it burns….
They may become a James Kook University. Keep up the hard work.
And I always thought that the temperature of the ocean reduced with depth.
I must be wrong because the fish would swim down a few inches if the water seemed too warm for them as they have no doubt done for millions of years.
Never mind. These scientists are very clever people – much cleverer than fish.
Fish control their surrounding water temperature by swimming upwards or downwards, just a few inches can make a big temperature difference.
The climate scientists studying these fish would have been right at home on the Ship of Fools.
I’ve done those tests – horrible, running on a treadmill while wearing a mask – bet the fish hated it.
1. Was there a control – to prove that the “scientist” knew how to keep fish alive in a tank? that the fish would not have died anyways? What about oxygen content in the tank versus a real coral reef.
2. as already pointed out, in past periods of warming, it was the high latitudes that warmed significantly, the equatorial regions only had minimal warming. So what is supposed to warm the tropics?
“In an era of rapid climate change, understanding the link between an organism and its environment is crucial to developing management strategies for the conservation of marine biodiversity and the sustainable use of marine fisheries.”
Rapid climate change? Like NO WARMING in over 17 years??
Oceans have warmed overall by 0.09 degrees since the 1950s. Yet they assume that the oceans are suddenly going to catapult into hundreds of times as much warming over the next 80 years? I think I spot one of many major flaws in that research.
David Chappell says:
“Given the craziness, should that university perhaps be re-named John Cook University?”
If they keep raising the testing temperatures, it should be the Fish Cook University and Seafood Restaurant.
Fish swim.
Fish use this mode of locomotion to move from one place to another place.
Fish use this freedom of motion to go wherever the hell they want.
Fish use this tactic to try and evade the top predator (man).
Fish will do ok.
PS. The greatest threat to fish populations is the rape of the bait fishes, to make snake oil like omega-3 magic potion.
My local super green grocery store charges double price for “organic” milk (contains carbon, but NO trans-Uranic elements); but you can then go to the next corner of the store and buy just about any kind of chemical food poison you want, to add to your milk; and 57 brands of squished baitfish oil.
Since when have the people indigenous to that area relied on the Damselfish or Cardinal fish Industry? Are they involved with Big Aquarium? Think of all the energy we’ll save when that heat comes roaring back! The fish will cook and wash up on shore for easy eating! If tiny tropical fish are even edible….sorry…this study is a joke…right? Right???