From York University – quite possibly the most poorly written science by press release I’ve seen this year. The leaps of “may” are profound, and the footbal team analogy is designed to elicit sympathy. I suppose if Daphnia populations were collapsing in lakes due to lack of helmets and shoulder pads, we’d see a collapse in the lake food chain too, but that doesn’t seem to be happening that I can find. And, as is typical with such alarmist press releases, they don’t name the paper, making anyone reading the press release have to go hunting for it.
Changes in water chemistry leave lake critters defenseless
TORONTO, Sept. 6, 2012 – Imagine that the players on your favourite football team were smaller than their opponents, and had to play without helmets or pads. Left defenseless, they would become easy prey for other teams. Similarly, changes in Canadian lake water chemistry have left small water organisms vulnerable to their predators, which may pose a serious environmental threat, according to a new study.
“At low calcium levels the organisms grow slower and cannot build their armour,” says study lead author Howard Riessen, professor of biology, SUNY College at Buffalo. “Without suitable armour, they are vulnerable to ambush by predators,” he says.
Riessen and colleagues, including York University biology Professor Norman Yan, studied the effect of changes in water chemistry on plankton prey defenses. Specifically, they examined how lower calcium concentrations affect
(water flea) exoskeleton development. These low calcium levels are caused by loss of calcium from forest soils, a consequence of decades of acid rain and multiple cycles of logging and forest growth. The results are published this week in the Proceedings of the National Academy of Sciences.
“Calcium is a critical element for Daphnia and many other crustaceans,” Riessen says. “Daphnia build their exoskeletons, which include some defensive spines, with calcium to protect themselves from predators. Where calcium levels are low, the Daphnia have softer, smaller, exoskeletons with fewer defensive spines, making them an easy snack.”
Why do plankton matter? Yan, the study’s senior author and a Fellow of the Royal Society of Canada, emphasizes that the tiny creatures are critical to our survival. “Without plankton, humans would be quite hungry, and perhaps even dead. Much of the world’s photosynthesis, the basis of all of our food, comes from the ocean’s plankton. The oxygen in every other breath we take is a product of phytoplankton photosynthesis,” says Yan.
This phenomenon of reduced calcium is also playing out on a much larger scale in the world’s oceans, he notes. “Increases in ocean acidity are complicating calcium acquisition by marine life, which is an under-reported effect of global carbon dioxide emissions. Thus marine plankton may also find themselves more vulnerable to predators,” he says.
The public is used to stories about changes in water chemistry that lead to large-scale fish kills, says Riessen. “These changes are more insidious. Daphnia might not be a household name, but they are food for fish, and they help keep our lakes clean. Changing the balance between Daphnia and their predators marks a major change in lake systems.”
So I found the paper, and sure enough, they don’t mention the oceans (in the abstract). Seems like they went a bit overboard with that press release.
Changes in water chemistry can disable plankton prey defenses
- Howard P. Riessena,1,
- Robert Dallas Linleyb,c,
- Ianina Altshulerd,
- Max Rabuse,
- Thomas Söllradlf,
- Hauke Clausen-Schaumannf,g,
- Christian Laforsche,h,2, and
- Norman D. Yanb,c
+ Author Affiliations
aDepartment of Biology, State University of New York (SUNY) College at Buffalo, Buffalo, NY 14222;
bDepartment of Biology, York University, Toronto, ON, Canada M3J 1P3;
cDorset Environmental Science Centre, Dorset, ON, Canada P0A 1E0;
dDepartment of Biological Sciences, University of Windsor, Windsor, ON, Canada N9B 3P4;
eDepartment Biologie II, Ludwig Maximilians Universität München, 82152 Planegg-Martinsried, Germany;
fDepartment of Precision- and Micro-Engineering, Engineering Physics, Munich University of Applied Sciences, 80335 Munich, Germany;
gCenter for NanoScience, Ludwig Maximilians Universität München, 80539 Munich, Germany; and
hGeoBio Center, Ludwig Maximilians Universität München, 80333 Munich, Germany
-
Edited by Michael Lynch, Indiana University, Bloomington, IN, and approved August 9, 2012 (received for review June 11, 2012)
Abstract
The effectiveness of antipredator defenses is greatly influenced by the environment in which an organism lives. In aquatic ecosystems, the chemical composition of the water itself may play an important role in the outcome of predator–prey interactions by altering the ability of prey to detect predators or to implement defensive responses once the predator’s presence is perceived. Here, we demonstrate that low calcium concentrations (<1.5 mg/L) that are found in many softwater lakes and ponds disable the ability of the water flea, Daphnia pulex to respond effectively to its predator, larvae of the phantom midge, Chaoborus americanus. This low-calcium environment prevents development of the prey’s normal array of induced defenses, which include an increase in body size, formation of neck spines, and strengthening of the carapace. We estimate that this inability to access these otherwise effective defenses results in a 50–186% increase in the vulnerability of the smaller juvenile instars of Daphnia, the stages most susceptible to Chaoborus predation. Such a change likely contributes to the observed lack of success of daphniids in most low-calcium freshwater environments, and will speed the loss of these important zooplankton in lakes where calcium levels are in decline.
===============================================================
In comments, Rat boy (who apparently has paid access) points out this last paragraph of the paper where they DO mention the oceans in passing, with more “may” caveats:
Marine plankton also face the prospect of reduced calcification,
in this case as an indirect consequence of ever increasing
concentrations of CO2 in the oceans (37, 38). Much like their
freshwater counterparts, many marine plankton also may find
themselves increasingly vulnerable to a variety of predators.
Thus, the indirect effect of changes in water chemistry on
predator–prey interactions in both freshwater and marine communities may play an important role in determining the ultimate success of species in these environments.
The point stands, they use “may” in the broadest sense in that paragraph to make that leap of logic, without any supporting science to back it up. If they had any supporting science, they wouldn’t use the word “may”.
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Gillian/BillD
The paper is interesting for what it studied. I haven’t read the entire paper, but I don’t have a problem with understanding this predator/prey relationship.
The speculation in the conclusion and the press release is a wild leap, and I can only hope that the paper was accepted in spite of those statements because the rest of the research is sound. There is no support for comparing an oligotrophic freshwater lake experiencing changes in nutrient run-off with un-measured, un-observed acidification of the ocean by CO2. Daphnia being more susceptible to this one predator doesn’t make them endangered (as I am sure you well know), nor does it put fisheries at risk. The Calcium shells don’t protect the Daphnia from fish predation. The midge larvae don’t live in lakes with lots of fish. Why? Probably because the fish have no problem eating them as well, and are capable of out-competing them for the Daphnia food source.
Just because this type of speculation has become the norm, doesn’t make it good science and good scientists should be disciplined enough to avoid it. It used to be that science students were taught to strictly avoid speculation in scientific writing. Welcome to the post-norm.
It seems somewhat strange that we would have a calcium shortage in the Great Lakes when great expanses of the shorelines and bottoms are limestone. The Niagara escarpment must surely be part of the watershed that would feed surface and sub-surface water to abutting lakes.
Oh well, science never ceases to amaze…
“This phenomenon of reduced calcium is also playing out on a much larger scale in the world’s oceans” … What? All those millions of tons of chalk, limestone etc. are running out? It really is worse than we think!
As for those “increases in ocean acidity”, I think it’s been noted here frequently that this is a very misleading description of a trifling non-problem. For a start, if the oceans ever got anything like “acidic”, the White Cliffs of Dover and all chalky rocks would be increasing the calcium content of the oceans very rapidly, as any fule no.
“Seems like they went a bit overboard with that press release.” Not half. Still, perhaps the “acidic” water will dissolve ’em before they get back on board. (With apologies to Bill D – I don’t really intend your pals to dissolve, of course … but then, it won’t happen 🙂
Sounds to me as though someone is testing the water – if you’ll pardon the pun – to see which direction the alarmism should go to generate new interest. People just aren’t panicking the way they used to. Even governments are beginning to frown at the costs and to pull away. They’ve got to find a new fear, a new worry, a new big stick to hit us all with. They’ve just got to. 97% of all grants may be involved. Oh panic, their source of income must not be allowed to die out. 😛
“York University”, it says.
My first thought was the University of York (UK) really has gone downhill in a big way*.
Then I saw “Toronto” …
*If anyone is interested see the Wiki article
Usually scientists don’t write the press releases and certainly editors and reviews have nothing to do with them. Yes, we are talking about lakes with very low Ca++, certainly not the North American Great Lakes. Try lakes in the Adarondack Mountains, in the Canadian Shield and in northern Norway. These are all places with lakes with very thin soils and granite bedrock. These are areas where low Ca is a problem for Daphnia and snails and other crustaceans and molluscs.. I really doubt that this paper has anything to say about CO2 and climate change. Lots of good research is hardly related to climate change. On the other hand, there is evidence that reduced pH due to CO2 entering the oceans is killing some marine molluscs, but that’s a different story. Quite a lot of good field and lab experimental work is gearing up among marine biologists on that topic. I’ve seen some good funded proposals. As that work is published, I’m sure that many of you will want to read the articles carefully and to comment.
Most ecological research is based on contributions to basic knowledge about ecology and evolution. I review a lot of grant proposals and only a small percentage mention environmental catastrophes. I want to assure you that scientists don’t like exaggeration. I’ve never even seen a grant proposal that contained any “alarmism.” Exaggeration and alarmism seems like a good way not to be taken seriously and to get a grant proposal rejected out of hand.
. So, Aly E above, I wonder what agency or institution is providing “alarmist” proposals for you to read or review (?). It’s not bad to have a tie in to an enviromental issue in a grant proposal, but grant reviewers are always looking at the quality of the science first. That’s my experience, mostly with the National Science Foundation, similar agencies from other countries and even more applied programs on water resources.
BillD says:
“I want to assure you that scientists don’t like exaggeration. I’ve never even seen a grant proposal that contained any ‘alarmism’.”
Then how did this alarmism and exaggeration attract so many grants??
More CO2 meanss more carbonate in the water and more calcium carbonate deposition. It is part of an extended equilibrium in which th e protons given off by the carbonic acid CANNOT affect tiself. Marine organisms are more resistant to pH change than these clowns want to admit. During the day, ocean pH in a bay or estuary can go from 8 up >10. This means that they are resilient regarding pH.
There is no evidence at all that CO2 can alter the pH of seawater, which is a complex buffer system that resists pH changes, particularly against a weak acid such as carbonic acid.
Do they realize that calcium is constantly being replenished in the oceans as erosion carries it from the land to the sea?
Being published in PNAS at all indicates that the paper has a 99.9% chance of being trash. Their publication of a paper based on consensus science, analyzing the peer-reviewed, not reviewed, number of papers, etc. shows that they no longer can discern between science, junk science and garbage. As if being peer reviewed is meaningful any more now that they allow pal view in its place.
footbal should be football.
Seems to me they are confounding many points. Asserting that low Ca is the problem, when forest SOIL is not where they live… they live in the runoff that will be higher in Ca as it’s leached out of the soil…
Then there is the leap to acidity (in an alkaline ocean…) causing Ca to be unavailable (a flat out assumption not supported by the facts) in an ocean where all that Ca must eventually end up. So much, in fact, that gigatons of it deposit as Limestone and Dolomite rocks globally (one of the major rock types of the crust) which then dutifully erodes back into, yes, the oceans…
It’s all part of the broken “Running Out” idea. Soil running out of Ca… We never “run out” of minerals and elements; the Earth recycles them….
Oh, and like the world needs more flies…
michaeljmcfadden says:
September 7, 2012 at 8:36 am
You and Dave Hitt lead me to this whole con. Can’t remember which of the two of you is the non-smoker & which is the occasional cigar man.
I had thought this had been dismissed years ago as rubbish, I certainly had way back, possibly the ’80s, can’t remember.
Anywho, fast forward from the ’80s to about 2007, I find the whole climate has changed, even though mine hasn’t. Well, it has but nothing I didn’t see before.
DaveE.
BillD
September 7, 2012 at 1:06 pm
###
Sorry no one is buying it. What we are witnessing is just more of the very thing that Socialists have been doing for 100 years. Propaganda works best when its multimodal and at saturation levels. By writing what you have all you are doing is demonstrating that you are a good little useful ‘tool’. I bet you even believe the silliness that you wrote.
higley7
September 7, 2012 at 1:47 pm
###
I used to raise daphnia for my many aquaria. One winter I kinda spaced one of my daphnia tanks that I had set under a tree during the summer. When I remembered to check on it it was December. The thing was full of pine needles and most probably, all of the water in it was urban rainwater from the monsoon storms. Its PH was around 5.0. The daphnia was just fine. I wonder if these jokers who call themselves scientist know that there are daphnia filled environments [where] the natural PH is 4.0!
Those fleas are poorly equipped to deal with Helvetica Scenario.
The pilot episode of “Look Around You” refutes this paper easily. “Calcium has a variety of uses, many of which are very important to humans. Perhaps its most important function is in human teeth, which are made of calcium. It is therefore integral to human survival, as without calcium, man would be unable to process food and would starve.” They additionally state “It is also important to never give any calcium to a gypsy . ”
http://lookaroundyou.wikia.com/wiki/Calcium
Any predators trying to eat the poorly defended fleas will also suffer from ‘Helvetica Scenario’ from living in the same calcium deficient water. This will result in the demise of all the predators of the fleas, being unable to eat because they don’t have teeth.
I grant that PNAS is a slightly better venue (IMO) than Science and Nature, but subject to the same incestuous “pal review” process that has reduced these previously fine journals to shadows of their former selves. When I say puff-piece, I mean that the paper states (even concludes with) speculative conclusions not based on verified scientific method supporting them. I am basing this, yes, on the press release summaries, since I would not pay for this “paper”.
The internet is the new standard for peer review. If a scientific paper cannot pass the muster of the blogosphere, then it is not peer reviewed, in my opinion. Let the sunshine hit it, then we shall see if it melts.
Scott says:
September 7, 2012 at 5:25 pm
“This will result in the demise of all the predators of the fleas, being unable to eat because they don’t have teeth.”
Well stated irony. Any deviation of an organism from the equilibrium population brings consequences that lead to a more fragile new population, since the homeostatic populations have adapted for eons to be the most energetically favorable, therefore stable population.
If they adapt a spiny hard skin, for example in response to a predator, this costs energy, perhaps motility, so it is less efficient. The genetic spread will always try to revert to the energy efficient state.
The new adaptation is temporary. Look at the Galapagos finch. When seeds become hard in dry times, the genetic spread allows for offspring with heavier beaks to break to seeds. But the finch population “hates” the heavier beak, since it costs loss of efficiency in other areas, such as preening or mating. Thus, when seeds become softer, the finch “can’t wait” to get a thinner beak and the population goes back to the starting, most energy efficient population (homeorhesis).
It’s funny that this has been used as evidence for evolution, but the finch adaptation is really anti-evolutionary. It keeps a finch as a finch, always within reach of the equilibrium, favored population, and always retaining the fringe characteristics in the genomic spread. Only after long ages of adaptation can a species change to a new set point, by losing some of the genetic information through disuse by the surviving offspring. The sifting out of these codons, which are usually multiple to ensure retention of adaptability in case the environment revisits the previous state, can take prohibitively long periods. The genome “wants” to retain versatility, with genes that can respond to the environment by turning on and off in response to signals (the quasi-Lamarckian paradigm).
I don’t have a problem with the use of words like “may” to express uncertainty in a scientific study.
I do have a problem when uncertainty is not expressed in “climate science”.
Gunga, “May” and “up to” are two of the favorites for “scientific propagandists” in pushing their arguments. The words fly right by the average layperson reading the story and simply translate into definites and normally-expected-numbers. “Increase” and “decrease” are used the same way: a University of Georgia study frightened many campuses into adopting outdoor smoking bans after showing a 162% increase in cotinine or somesuch among “students exposed to outdoor smoke.” The fact that the change was from virtually zero to STILL virtually zero (think nano and picograms, and also that it occurred only after six hours of sitting in the middle of a “smoke pit”) flew right by the average person: all they remembered was “massive increase in a poison of some kind” in their thinking: just as the propagandists intended in spreading the story.
The one thing that would lead me to take this story seriously is that I don’t think there are any big white-roof/black-roof lobbying/granting organizations out there pushing researchers to come up with the “preferred results” (though heck, maybe there ARE a few and one of them sponsored this!)
– MJM
If they had any supporting science, they wouldn’t use the word “may”.
———-
But there is a contradiction.
Because when scientists don’t say may there is much exercise of the “science is not settled” debating point. That’s why I to disregard all of the huffing and puffing and obsessive need to point score that amounts to zero points.
http://hahana.soest.hawaii.edu/hot/hot-dogs/public/hd134739.gif
Is the shallow water pH following the atmospheric CO2 increase?
Transparent pond life is always fascinating. The water-fleas are very interesting too.
Also, I wonder what the pH is in the unknown sink that contains the accumulated ~50% of anthropogenic CO2 that goes AWOL every year?
Speaking of fleas……
Fleas from 230,000,000 years ago found ‘preserved’ in droplets of amber, 100,000,000 years older than the ones from “Jurassic Park”
http://io9.com/5938448/these-230+million+year+old-bugs-preserved-in-amber-are-the-oldest-yet
Tadpoles vegetarians? Frog spawn (in a tank) … lots of tadpoles … a few very large tadpoles… no sign of any others! Where’d they go?
Anthea