Guest essay by Eric Worrall
A study by University of Queensland Professor Craig Franklin claims that crocodiles may be endangered by global warming.
According to the Press Release;
Professor Craig Franklin of the UQ School of Biological Sciences said saltwater crocodiles exposed to long-term elevated water temperature spent less time submerged once water temperature exceeded 31.5 degrees Celsius.
“We thought that crocodiles – like many animals – would adjust to temperature changes so life continues,” he said.
“However, we were surprised to find they had little capacity to compensate for water temperature changes and seemed to be hard-wired to operate at certain temperatures.
“We are not sure what this means, but it’s likely that if the water is too hot, crocodiles might move to cooler regions, or will seek refuge in deep, cool water pockets to defend their dive times.”
Read more: https://www.uq.edu.au/news/article/2015/12/hot-water-puts-crocs-risk
The abstract of the study;
Diving in a warming world: the thermal sensitivity and plasticity of diving performance in juvenile estuarine crocodiles (Crocodylus porous)
Essie M. Rodgers, Jonathon J. Schwartz and Craig E. Franklin*
Air-breathing, diving ectotherms are a crucial component of the biodiversity and functioning of aquatic ecosystems, but these organisms may be particularly vulnerable to the effects of climate change on submergence times. Ectothermic dive capacity is thermally sensitive, with dive durations significantly reduced by acute increases in water temperature; it is unclear whether diving performance can acclimate/acclimatize in response to long-term exposure to elevated water temperatures. We assessed the thermal sensitivity and plasticity of ‘fright-dive’ capacity in juvenile estuarine crocodiles (Crocodylus porosus; n = 11). Crocodiles were exposed to one of three long-term thermal treatments, designed to emulate water temperatures under differing climate change scenarios (i.e. current summer, 28°C; ‘moderate’ climate warming, 31.5°C; ‘high’ climate warming, 35°C). Dive trials were conducted in a temperature-controlled tank across a range of water temperatures. Dive durations were independent of thermal acclimation treatment, indicating a lack of thermal acclimation response. Acute increases in water temperature resulted in significantly shorter dive durations, with mean submergence times effectively halving with every 3.5°C increase in water temperature (Q10 0.17, P < 0.001). Maximal dive performances, however, were found to be thermally insensitive across the temperature range of 28–35°C. These results suggest that C. porosus have a limited or non-existent capacity to thermally acclimate sustained ‘fright-dive’ performance. If the findings here are applicable to other air-breathing, diving ectotherms, the functional capacity of these organisms will probably be compromised under climate warming.
To their credit Professor Frankly et al put some fairly strong caveats in the body of the study itself, for example;
The deleterious effects of climate change on ectotherms may, however, be counteracted by compensatory responses. Thermal stress can be buffered by both behavioural and physiological strategies. Pockets of thermally favourable habitat can be sought out or shuttled between to maintain body temperature within a preferred thermal range (Seebacher, 2005; Seebacher and Franklin, 2005). Alternatively, long-term changes in thermal regimens (e.g. seasonal shifts in temperatures) can induce physiological changes, where the thermal effects on biochemical processes are blunted (Johnston and Dunn, 1987).
Read more: http://conphys.oxfordjournals.org/content/3/1/cov054.full
I think I’ll go with the caveats on this one. Crocodiles are a survival of a much warmer world – for example, crocodiles were far more prevalent in the Cretaceous Period, which lasted from 145 to 66 million years ago, was on average 4C hotter than today, and had an average CO2 level of 1700ppm, over 4x higher than today. The largest crocodile which ever lived, twice as big as the largest modern species, enjoyed a widespread habitat during this warm period.
In addition, many species of crocodile, such as Australia’s infamous salty, can swim 100s of miles in a month – so they would have no difficulty migrating to more comfortable habitats, if their current habitat ever becomes unsuitable for any reason.
“Climate Change is Endangering Crocodiles”
Well they are rather delicate creatures….
Not to mention not endangered enough yet to not be a delicacy in fact…
Yes, I have yet to try croc. Done roo, will try emu too. Australia, the only country I know that allows people to eat the animals depicted on the nations emblem.
Aye, bloody luverly….sorry, meant tragic….
It’s the best way to preserve a species, far it, eat it!
Farm it…
Could be that crocks cause climate change. Consider that alarmists accuse us of causing climate change because we eat meat. What do crocks do? And lions and tigers. Hey, maybe it’s not us after all.
So to summarize; the species the Gaia worshipers have proscribed are:
– The Polar bear
– The Wolf
– The Crocodile
– The Brown (Griz as we call them) Bear
All of which feed on humans and their children and would also prefer a 90% reduction in humans.
I can’t say this comes as a surprise. Not at all. It confuses me the general population can’t see this, but then we’ve all witnessed a sample of bikini clad women on Venice beach promoting Sharia law in support of Hillary Clinton’s policies so I fall into the category of people for which it should not come as a surprise.
One is more at risk from the funnel web spider in Queensland than a croc. Croc’s live in wetlands. Funnel webs live in ya garden. Won’t someone puhlease think of the funnel web spider??!
Except that funnel webs only live in a small area of NSW, from Newcastle to Wollongong.
p.s. NSW is the state to the south of Queensland.
Nup, Funnel Web spiders can be found in Queensland as well. http://www.couriermail.com.au/news/queensland/queensland-alert-over-giant-funnel-web-sightings/story-e6freoof-1225794850537
Having said that, they’re probably less of an issue in Queensland. Most Queensland householders drench their houses in powerful long lasting insecticide every few months, to stop ants and cockroaches. The spray also seems to kill most spiders, as well as making me sick as a dog when I use it, for the rest of the dayl…
It only took 50 years for this Hypothesis and consensus to be disproven after every one is sick and on multiple drugs. https://www.google.ca/search?q=time+magazine+cover+on+cholesterol+1984&biw=1024&bih=514&tbm=isch&imgil=9U_egjUAgYCeTM%253A%253B6gZPpszv48eLiM%253Bhttp%25253A%25252F%25252Fblog.primalpastures.com%25252Funcategorized%25252Ftime-magazine-says-eat-butter%25252F&source=iu&pf=m&fir=9U_egjUAgYCeTM%253A%252C6gZPpszv48eLiM%252C_&usg=__4IZzQ67fxM_LIyCr0raEhCrhS3Q%3D&ved=0ahUKEwis26T42ufJAhVLJiYKHTbNAbwQyjcIOA&ei=vjB1VqyEKMvMmAG2mofgCw#imgrc=9U_egjUAgYCeTM%3A&usg=__4IZzQ67fxM_LIyCr0raEhCrhS3Q%3D
Here is the article on the 50 year lie Judith Curry used this as an example.http://blog.primalpastures.com/uncategorized/time-magazine-says-eat-butter/
science has gotten so many things wrong over the years based on a single study. Mann’s hockey stick will end up in the same rubbish pile as Keys 7 countries study.
As so many studies in science it is never the one report showing a positive result. It is the one report showing a negative result that is important.
But the press and scientists have had it backwards for 100 years. They sensationalize the positive results, as though they were some great new undiscovered truth. when in fact a single positive result means almost nothing, while a single negative result is proof.
http://blog.primalpastures.com/wp-content/uploads/2014/06/photo-2.jpg
7 degrees of WATER temp change is their high case? Bugger me. Why not test them at 60C? “UQ findings: Crocs don’t like being boiled.”
A study by University of Queensland Professor Craig Franklin claims that crocodiles may be endangered by global warming. Can you see how it is so easy to create a panic to attract more funding for a new fabricated concern?
Franklin must be an absolute idiot if he does not know that crocodiles have experienced some of the harshest climate changes that have occurred going back in time. Today’s climate changes are mild in comparison.
Franklin should learn from one of the world’s leading real crocodile experts, Dr Graham Webb of the Northern Territory of Australia, who can educate Franklin about it.
Mervyn
Bindi and her brother Bob Irwin could educate Dr Franklin about Crocodiles.
And dancin’ too.
Franklin must be an absolute idiot
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fishing lures are designed to catch fishermen (who buy them). they are only secondarily concerned with catching fish.
similarly, scientific studies are designed to catch funding bodies. they are only secondarily concerned with catching facts.
Excellent analysis!
“Air-breathing, diving ectotherms are a crucial component of the biodiversity and functioning of aquatic ecosystems, but these organisms may be particularly vulnerable to the effects of climate change on submergence times.” Air-breathing, diving ectotherms may learn how to fly instead of diving. Not likely but it may happen.
Russell
December 19, 2015 at 3:03 am
“Here is the article on the 50 year lie Judith Curry used this as an example.http://blog.primalpastures.com/uncategorized/time-magazine-says-eat-butter/”
I think we are turning the tide on CAGW and the harms of CO2, which appear, rather to be benefits to the biosphere. But yes it’s a cling on sort of thing that weathers adversity, just like the crocodile does. When a layman like myself can identify crappy science in broad spheres of knowledge, you know there isn’t much sophistication out there.
As an aside, I think I might have identified a characteristic of the skeptic personality in the butter/cholesterol chicanery. Despite the bombardment of “settled science” with 97% certainty, I never got caught up in this. I’ve loved butter, steaks, chops, bacon, the crispy fat (called crackling by my grandmother) and apple pie with a flaky crust made with lard. I even created a recipe (among others) that would have scared the life out of the folks with the calorie counters. I called it Bearbrook Puffs (my farm was on a little creek called Bearbrook in eastern Ontario). I cooked a load of bacon from my own-raised hogs, chopped it up, grated cheese, made a Yorkshire pudding-type or crepe-type thin batter with loads of eggs and milk and some flour, heated the oven to a high heat (450? – it was a wood cookstove). I preheated a roasting pan with the shallow sea of bacon fat in it until it was good and hot, mixed up all the ingredients in a bowl and dumped it into the hot fat and shoved it back into the oven. It swelled to a pan-filling size and browned nicely. I cut this hollow crispy treat up for my family (six kids [plus 2 more for a couple of years] and wife and myself). They loved it, as is, or with our own-make maple syrup.
I’ve lived through 7 decades plus sampled 2 more on either end and I’m still healthy and working in mining consulting. Granny lived to 97, mother in to her nineties. Now the secret in addition to genes is along with fatty foods, we also ate a large variety of vegetables, fruit, fish and got lots of exercise. I think skeptics come from self-motivated types. I never joined any fraternities, student governments, benevolent orders of various animals, masons, etc. etc. Naturally ‘Individualist’ would probably describe most skeptics, possibly at least mildly eccentric).
Skeptics can also be annoying!
I’m with you. Besides, I don’t want to belong to any club that will accept people like me as a member.
I live in Florida where we have far too many alligators. Believe that Crocs & Gators have been around for many millions of years. Seriously doubt a 2C, or even a 10C, increase will pose a serious threat to either.
Bill
Gee, I guess there are no Crocs in Canada because it is sooooooooo hot in my Igloo I had to open all the windows !!
I have a slight problem with the introduction to this otherwise interesting introduction to the delights and perils of Australian life.
It concerns the comment that during the Cretaceous the temperature was about 4 C higher than today , with 4 times the CO2 concentration .
Now I appreciate that the land mass and ocean circulation was different then and that a simple radiative forcing equation without feedbacks is but a crude simplification , but I cannot reproduce the figures given above using the equations for CO2 forcing from ScepticalScience.:-
Change in temp (K) , dT = lambda * dF where lambda = radiative forcing by CO2
dF = 5.35 * Ln(C/Co) where C/Co is the ratio of CO2 concns ,
If lambda = 3 +/- 1.5 K/W.m^2)
Ln(C/Co) = Ln4 = 1.386
then dT = 11 to 33 K depending on the figure used for lambda . Much higher than any paleotemperature I have read about , so have I miscalculated , are ScepticalScience equations not appropriate , or are there massive negative feedbacks .
mikewaite December 19, 2015 at 8:11 am
You didn’t account for the fact that e-e-e-e-vil anthropogenic fossil-fuel generated CO2 is a magic gas. Right there is your problem.
http://media.photobucket.com/user/radlein/media/math07.gif.html?filters%5Bterm%5D=miracle%20occurs%20cartoon&filters%5Bprimary%5D=images&filters%5Bsecondary%5D=videos&sort=1&o=2
Don’t forget that climate change is also triggering volcanoes.
http://time.com/3687893/volcanoes-climate-change/
http://www.eurekalert.org/pub_releases/2015-12/uow-1rs121815.php
I’d like to see the study methodology, to see if they accounted for a couple of changes to the crocs that I would expect.
1. When they put these juvenile crocks in the tank, I’ll bet the little tikes were scared to death. Over time, they would feel safer in their new surroundings, meaning they probably wouldn’t stay under as long. If the tank temp started off at 28 for a week, was raised to 31.5 for another week, and finally was raised again to 35 for the third week, then I would expect much (most) of the fright acclimatization was due to poor study design.
2. Juveniles are young. They may have a natural tendency to use fright diving for protection more at younger ages. I would expect that, as they get older, they naturally would become less timid. Just as above, not accounting for this variable could give bogus results.
I am confused now. Just a few months ago I read that crocodiles would be come badder and bigger with global warming:
http://www.nature.com/ncomms/2015/150924/ncomms9438/full/ncomms9438.html
Umm… How did they survive when there was no ice on the planet at all then?? They’ve been around for millions of years…. Did I say when there was No ice on the planet and it was sweltering hot 24 hours a day for millions of years….. How can I make money from this as well???
Say, what!?
“‘fright-dive’ capacity” – Translation, they frightened the little beasts so they would dive under the water in fear.
“(Crocodylus porosus; n = 11)” – Translation – 11 little crocodiles.
Translation – Crocs were repeatedly frightened so they would dive into different water temperatures ranging from 28°C (82.4°) to 35°C (95°F)
The researchers claim, that the juvenile crocodiles, stayed underwater for less times as the temperatures got warmer.
Did any of the researchers bother using a control group? Or several groups of young crocodiles?
There wouldn’t be a chance that the little crocs got wise to the science buffoons trying to scare them under the water? And that the dive times are related to the little crocs just not being afraid any more?
All crocodiles like to sun themselves. Little crocodiles are less likely to sun themselves on open beach; mostly because little crocs that do sun themselves in the open end up as bird food, Tasmanian devil food, bigger crocodile food, even toad food.
Perhaps the researchers for the article above had their thumbs bitten too many times by the little crocs and all of their thumb sucking shrunk their brains…
Methinks you’re right. The researchers also didn’t give the crocks time to “adapt” over a number of years. Seems rather abusive of the reptiles as well.
Still, the study is good for something.
Think of the jokes this study will produce.
“This study is a crock”
“This study crocks me up”
You get the idea, lol…
I’ve heard crocks drown their prey, then wedge it under a tree or something till it begins to rot, then they feed on the softened flesh.
They’ve only been doing it for millions of years, I imagine by now they know the best methods ?
Looks more like a Gharial to me….and I’m quite sure they’ll survive warmer water. The ones that are here have “been there, done that” – because it was warmer before.
I admit that the behavior of some animals can be changed by the climate change, but still, if the animals change their ways, could be just evolution. Animals changed habits even before human intervention on climate. Global warming started way back, around 150 years ago, when human intervention was minimal. Earth has a cycle of warmer and cooler periods. Now we are in a period with higher temperatures, probably a hundred years from now we’ll see a different behavior at some species.
There must be a reason they are basically armor plated.
Sharks ??