Research looks at warming, browning effects on freshwater systems
DARTMOUTH COLLEGE
HANOVER, N.H. – October 25, 2021 – Climate change impacts on freshwater systems can lower nutrition and increase toxicity at the base of the food web, according to research from Dartmouth College and the Swedish University of Agricultural Sciences.
The research, published in Scientific Reports, focused on the effects of warming water temperatures and browning—a discoloration of water caused by increased dissolved organic matter—using controlled outdoor environments known as mesocosms.
“Climate change scenarios predict increases in temperature and organic matter supply from land to water,” said Pianpian Wu, a postdoctoral fellow at Dartmouth and lead author of the study. “For the first time, we used manipulated mesocosm systems to test the effects of warming and browning.”
Under the expected climate scenario of more warming, changing precipitation patterns, and higher levels of dissolved organic matter, the study looked at the fate of nutritious polyunsaturated fatty acids and toxic methylmercury in the food chain.
The research found that a combination of warmer, browner water resulted in the higher transfer of methylmercury from water to phytoplankton at the base of food web. Lower concentrations of essential polyunsaturated fatty acids in phytoplankton were also observed.
Long-chain polyunsaturated fatty acids—such as omega-3 and omega-6—support the growth and survival of animal and plant life by providing energy and by regulating immune systems. Methylmercury is a form of mercury that is easily absorbed by living organisms and acts a potent neurotoxin.
“The reduction of polyunsaturated acids at the end of the mesocosm experiment with both warming and browning effects was concerning,” said Wu, who began the research as a PhD candidate at the Swedish University of Agricultural Sciences.
Phytoplankton are the main suppliers of polyunsaturated fatty acids in aquatic ecosystems. According to the study, the less nutritious phytoplankton that result from browning and warmer water cause higher-level organisms—such as zooplankton, fish, other wildlife, and humans—to be exposed to more methylmercury as they consume more to achieve fatty acid quotas.
“This study shows that the food quality at the base of aquatic food webs deteriorates with climate change,” said Kevin Bishop, professor at the Swedish University of Agricultural Sciences and the senior researcher of the study. “The research is important because it places food web investigations within the context of active global change processes.”
While previous research on browning and warming has been conducted in natural environments, this is the only study to rely entirely on controlled mesocosm environments.
The researchers used 24 thermally insulated plastic cylinders to test the effects of various levels of warming and browning under four different scenarios, including a reference scenario without any weathering effect. The mesocosms were controlled at subalpine conditions that are highly prone to climate change effects and relatively poor in dissolved organic matter.
“The use of mesocosms to investigate questions related to ecosystem effects of climate change is particularly important,” said Celia Chen, research professor at Dartmouth and a co-author of the study. “The effects of factors such as temperature and browning can be tested individually and in combination while controlling other environmental conditions. Mesocosms also eliminate the need to travel long distances for field investigations.”
The study was conducted at the WasserCluster Lunz research facility outside of Vienna using lake water from Lunzer See in Lower Austria.
According to the research team, the findings point to the importance of factoring consumption levels in addition to concentration levels when looking at the quality of the food web in freshwater systems.
Martin Kainz and Katharina Winter, from WasserCluster Lunz- Biologische Station; Fernando Valdés, Uppsala University; Siwen Zheng and Rui Wang, Tongji University; and Brian Branfireun, Western University all served as co-authors of the study.
JOURNAL
Scientific Reports
DOI
ARTICLE TITLE
Elevated temperature and browning increase dietary methylmercury, but decrease essential fatty acids at the base of lake food webs
ARTICLE PUBLICATION DATE
19-Aug-2021
I can only hope that we have reached peak Wokeness and Numptiness, but the depths of folly have not yet been plumbed.
Unfortunately, all indications are that woke and morally broke is a progressive condition.
Nice double entendre.
Get woke, go broke, in every sense of the term.
Agree. Just more peer-reviewed junk science. Even the Weather Channel is spreading false information … https://www.youtube.com/watch?v=HQKbm4qU_lQ
Especially the WX Channel!
The biggest falsehoods the Weather Channel spread is (1) they are accurate and (2) they are trustworthy. TWC couldn’t accurately predict 12:30 at 12 noon. They have been caught lying about the severity of storms several times — i.e. a “reporter” having trouble standing in the wind while people behind him just casually walk by. It is no wonder their founder disavowed them before he died.
“Even the Weather Channel is spreading false information …”?
The Storm Channel has been spreading false information for over a decade now.
they have for years.They do it regularly with any storm system coming to Florida.
Watching TWC is like watching a bunch of animated cartoon characters trying to put on a skit that’s supposed to be serious & fails badly….. Like pre-school badly.
More plant food in the air means more plant mass. Protein content therein depends upon N content, hence we need more nitrogenous fertilizer from fossil fuels to take maximum advantage of increased carbohydrate in our crops.
Green Meanies either have not an inkling of science, hate humanity, or both.
“Weekend At Brandon’s” is a movie regularly featured on all MSM channels.
If there is still lots of money in it the flow of drivel will continue.
How real were the simulations? As it was based on alpine lakes, one would assume a much different flora than a naturally warmer body of water.
Deary me. It is amazing what 0.007C rise per year can do. Did they check what happens during the ‘Pause’. It’s been going on for about 7 to 8 years now.
So if you eat food from equatorial regions it has poor nutrition and also might poison you? This idiot report is a non-starter. Dartmouth?
Good point. If their research is accurate then they should find this as the normal condition in the tropics.
“Yes, we want no bananas!
We want bananas today!”
(And you could include oranges, lemons, coffee, tea, grapefruits, avocados, etc.)
They don’t have to go that far. I doubt if any of them have seen, much less studied, the black water rivers in the low country of South Carolina.
Plastic tubes? And did they declare their dependence on oil products for this study? And, like the study on ‘ocean acidification’, does this study also depend on highly unrealistic concentrations to achieve their predetermined target? I actually thought Halloween scare stories were a week away!
My research suggests that a frog’s hearing depends on its number of legs because after I cut off all four of its legs, and I yell “jump frog,” it no jump.
Congratulations, Scissor, you are promoted to Political Scientist Level 1.
My brother heard a version of this with grasshoppers. The interesting thing is that grasshoppers actually do have some of their ears on their legs .
I’d heard a similar version involving, I think, fleas. Yell “jump” and slap the table. Measure the distance after each leg was removed.
The study’s conclusion after all the legs were cut off?
“Flea can’t hear.”
They talk as if there is only one climate on earth. There are 18 plant hardiness zones just in the US alone.
That’s what happens when you have blinders on, and have determined what your report is going to say before you ever study it. And then, you forget to study it and just make computer simulations with vague inputs, and with the output you predetermined. Wonder how many simulations it took to get the desired output.
How did the world survive without humans?
About 2 million years ago when something like a human showed up, since that time humans and polar bears evolved, and the world has became colder.
Or in world before humans, the world was much warmer {lot’s a global warming} somehow life survived without world being so cold.
Stop that train of thought. You’ll have some woke climate enthusiast declaring that cooling is 100% down to humans and the world was a paradise before we turned up!
I have seen lots of data saying the earth was warmer a few thousand years ago. I wonder how humans managed to survive under those conditions, and without the technology to do anything about it.
Humans successfully survived in every hot climate on Earth. It was only Antarctica that was devoid of humans before the industrial revolution.
Since it is not warming in these fresh water bodies, what are they measuring?
Having been through the Dismal Swamp Canal with its very brown waters, the kush growth all around belies that it is bad for pants. In fact it’s more like liquid topsoil.
As a lipid biochemist, I have never heard that polyunsaturated fatty acids (PUFAs) are essential nutrients. Actually, if it was warming, they would adapt by having less double bonds and thus less PUFAs. Coconut oil is from the tropics (duh) and is mostly saturated and monounsaturated fatty acids. PUFAs are a survival trait for more temperate climes.
I’ve been in brown water lakes all over the east coast of the US. New Jersey Pine Barren lakes are all clear brown and surrounded by lush vegetation of all kinds. The same for the Florida lakes with all the cypress trees, the water in Big Cypress is clear brown and supports a huge and varied ecosystem. These guys need to go back to school!
It is schools that are doing this to budding “scientists” worldwide. Pumping hot water, organic materials (?) and mercury (?) into plastic tubs is some idyllic alpine meadow is not experimentation in the real world.
It reminds me of all the smoking experiments they did on poor defenseless rats … with concentrations so high there was almost no air left, but not a single one developed cancer.
They learned how to do this from Scripps with their huge salt water tanks in the basement. In controlled experiments to can achieve nearly any result you want by altering your recipe. A little more of this a tidge less of that, add heat and pressure and bingo, planetary disaster on a biblical scale!
Progressives sleep better just knowing “it’s worse than we thought”.
“Climate change impacts on freshwater systems can lower nutrition and increase toxicity at the base of the food web.”
“Can”, not “will”? What a deeply predictive “science”.
““Climate change scenarios predict increases in temperature and organic matter supply from land to water,”(my bold)
Tedious speculations about the physically meaningless. That pretty much describes all global warming scenarios.
‘We assume everything goes to hell in a handbasket. Our model says that when everything is assumed to go to hell in a handbasket, everything goes to simulated hell in a simulated handbasket.‘
Real reactions to simulated disasters require real money, though. There’s the rub for the payers, and the attraction for the simulators.
I often wonder how often some of these so-called scientists actually get outside their basements and labs.
The Mississippi River has a nickname of “Ol Muddy”. It’s waters aren’t clear, they are MUDDY. And in empties into the Gulf of Mexico carrying all that “stuff”. It must be continually dredged at the Gulf and upriver to remove all that mud in order to make the river and port useful.
And yet that area of the Gulf has great hatcheries and fishing. I know of no one that has claimed shrimp from around that area of the Gulf are “poison” to humans!
All this “may cause” stuff is just scaremongering to get more grant money. Greed and power-seeking has permeated so much of climate science that it is no longer recognizable as “science” at all.
The Wokerati keep saying ludicrous things and then are outraged when we laugh and ridicule the “experts.”
“The research is important because it places food web investigations within the context of active global change processes.” Wow, they did open a can of worms, the kind that survive. Such webs rather complicated chemically and otherwise. Well at least I learned a new word-–“brownification.” Don’t go there, but actually the most productive states are along the Mississippi River, waters mostly turbid.
From the paper—
“However, the “wall effect” could change the mass balance such that there would be a lower mass percent of the total MeHg mass in the microplankton. In addition, the “wall effect” could have also resulted in biomass dilution of the MeHg concentrations in the microplankton fraction shown in Table 1, resulting in lower MeHg concentrations comparing to where no or less “wall effect” occurred…..Hence, we are here able to add a mechanistic understanding of the combined effects of warming and browning to the observations on MeHg bioavailability and lipid content under climate change. Moreover, we connect predicted climate-change factors with environmental consequences in aquatic ecosystems.” OK!
Just like they have predicted the Artic would be ice-free by now, that polar bears would be extinct by now, that we would have more famine around the world, that we would have more droughts, that we would have more floods, that NYC and Miami would be underwater by now, etc.
None of which has happened, not even close. And we are supposed to put some kind of stock in this “prediction”?
These people don’t even know if the “average global temp” is going up from higher maximum temps or higher minimum temps. Their whole experiment is based on expecting higher maximum temperatures. Yet the actual evidence today, supported by a string of record global food harvest over the past 20 years, supports higher minimum temps and not higher maximum temps. Which becomes a *much* harder experiment to conduct – which is probably one reason they just make the simplifying assumption of higher max temps!
The reality is it appears the number of days above 90ﾟ has been going down since the 1930s. Overnight lows have been increasing. It may really just be that the climate is becoming more moderate.
As Tony Heller posted- the alarmists have flagged up that every country is heating up twice as fast as every other country.
“Twice as fast”
The study results and it’s methylmercury concerns are sort of real, but the inferred climate alarm is bogus, at least for the US and Europe (maybe not China). I just researched and updated my knowledge on this before commenting.
The main source of environmental mercury is coal burned for electricity generation. That why EPA regulated starting 1990, with full compliance (wet scrubbers also used for SO2) by 2007. Depending on the coal burned, these reduce mercury emissions by 60-90%. So mainly a legacy problem except in China and India, steadily reduced over time by natural processes.
Environmental Mercury is converted to trace toxic methylmercury by bacteria in warm water, which then accumulates up the food chain, with the largest amounts in large ocean fish predators. Even then there is no general health issue. The LNT toxicity model does NOT apply. Methylmercury in potentially ‘toxic’ amounts could not even be measured until analytic chemistry advances about 1995, and provably eating normal amounts of ocean fish with ‘high’ (meaning minute) amounts of Methylmercury (tuna, swordfish, mackerel, shellfish) causes no harm whatsoever.
The chance that this could ever be a freshwater fish consumption problem is about Zero. The omitted background information makes a ‘real future problem’ just more unreal so bogus Ivy League alarmism. Shame on Dartmouth.
Thanks for that, Rud. When reading the article, I vaguely remembered the fish/mercury scare was debunked some time ago.
The only instance of severe consequences of mercury poisoning was in Minamata Bay, which was industrial contamination (PVC production) in a country known for its fondness for sashimi (raw fish).
There is not a single well-documented instance of methyl mercury poisoning in the US, despite the EPA finding many localities with ‘high’ levels of mercury in the local fish. That is probably because Americans cook their fish, out of an abundance of caution about fresh water flat worms. Methyl mercury has a boiling point the same as water. Therefore, cooking fish undoubtedly drives off most of the methyl mercury. When I was involved in a study looking for methyl mercury in well water in the New Almaden district (Calif.), the lab I contracted with warned me that if I intended to provide them with any fish for analysis, to freeze the fish if I couldn’t get it to them withing 24 hours because the methyl mercury was very volatile.
I have spoken with a Sacramento USGS employee responsible for researching mercury left over from 19th C gold mining. Although metallic mercury is abundant in the rivers and streams of the Mother Lode, he said that he had never observed any deleterious effects on the wildlife, unlike at Minamata Bay.
On the other hand, there is a well-known instance of a researcher at Dartmouth who died after getting a single drop of di-methyl mercury on her hand, through double-layer gloves. It is extremely toxic! Common methyl mercury, not so much, particularly at the levels found in fish.
“The main source of environmental mercury is coal burned for electricity generation.” Wrong that only 2% of the total the other 98% comes from the oceans. I figure out a long time ago power plant were never the problem because there never been a plume effect on mercury levels from a coal fired plant. The mercury is normally well distributed, unless the soil is saturated for some other reason man made(old industry plants or paper mills,not power plants) or nature(volcanic soils.)
We need more petroleum to feed the base of the food web. Nutritious, green, organic.
“This study shows that the food quality at the base of aquatic food webs deteriorates with climate change,”
That’s all I need to read to know what utter crap this paper is. The implication if taken literally is that any change in the climate from the present leads to things getting worse. Of course they meant to say warming but dropped the plot there due to the warming not coming along as predicted. That also means none of the other predicted changes can be counted on, but that doesn’t stop them from forcasting a dire future due to the changes they find in their rigged ecosystem when the predicted changes suddenly appear like magic in the real world. Another chapter in the “Academics” who cried wolf.
They will likely proceed to claim that their theories explain all the “starvation” during the little ice age in the 1600’s
These people are lunatics. Proof positive science studies have gone awry.
These problems are only caused by man-made climate change. Natural climate change wouldn’t cause this.
“Climate change lowers nutrition then increases toxicity at the base of food web”
Apparently their hypothesizing is as bad as, or worse than their grammar!
When the climate changes, as it ALWAYS does, opportunistic species take advantage of the changes or new species evolve to do so! Why do we still see the greatest proliferation and diversity of Life mostly in the hottest regions? Because that is where most species evolve, and then they adapt to other regions based on nutrient availability and overcoming obstacles to survival like cold! The nutrients provided by ocean upwelling can make the Pacific off South America teem with fish; but a shift in the ENSO can make it all disappear in a trice!
It seems that the authors of this study missed out on a number of basic concepts in their education. Perhaps they should take a trip to the Galapagos to gain a deeper understanding of how Life tends to take advantage of every option! Maybe being left there for a few years would give them an appreciation of the advantages that fossil fuels and other reliable energy sources have provided for the developement of human civilization and prosperity!
Nah, probably not!
Mesocosms? Bwahahahaha!
They’re 55gal plastic barrels with foam pads! I have 3 and can get more if anybody wants to go into the “mesocosm” biz.
“Controlled outdoor environments”. Bwahahahaha! Rain barrels! The skeeters love them so I turn them upside down.
The Science is a farce. Dartmouth ought to be cancelled. Too stupid for words. And they all flew to Austria to do the rain barrel research. Wouldn’t that money be better spent by burning it in local burn barrels?
Looking at the picture of the setup I, too, thought it an ideal place to campout for a few weeks.
Exactly. Heating up “stuff” in rain barrels without properly functioning ecosystem processes means exactly nothing.
There was a time in my life when Dartmouth had a good academic reputation. That was one of the reasons the Army established their Cold Regions Research and Engineering Laboratory in Hanover (NH).
They’re constantly banging on about “climate change” this and “climate change” that. Which “climate” are they referring to … or are they just talking out of their collective ass? Sooner or later these “climate” geniuses needs to define their terms. I’m tired of trying to guess what they mean. The nonsense they produce in all this so called “peer reviewed science” surely can’t apply uniformly over the entire planet.
Would anyone trust Panpan to babysit their pet goldfish over a weekend?
nah. me neither
Sadly she is in for unhappy times as she ages if she imagines that polyunsaturates in the shape of Omega 6s or 9s are nutritious, essential or healthy.
Sorry hun, for critters like us they are Liquid Cancer
Slightly better for us than eating refined sugar but only ‘slightly’
I ventured into the ‘proper’ articles and they tell us the lake water had a pH of over 8
No no no, that is insane and especially for water with any organic matter in it = the ‘browning’ she talks about.
The natural biologic decomposition of that material would/does produce organic acids (generally referred to as Humic Acid by horticulturists **) and those would drop the pH to 5 or even less.
** Sorry again Panpan, you should have known that.
Too busy walking, hiking and having a good time around that lovely landscape I expect
There is something really very wrong in there, even before filling barrels with dirty water and expecting anything less than disgusting rotten stink to overtake them.
PS That is exactly what happens inside our own intestines when/if we eat a lot of plant material and ‘fibre’ – you have been warned, and not for the first time by Yours Truly
(Its why you fart and, the smellier they are, the more trouble you are presently in and making for your future self)
Oooooh now then.
Is rotting decomposing plant material inside us mobilising Mercury (a neurotoxin do you say?) that would have otherwise gone straight on through and out?
Nah, surely Shirley not, Fibre is Good For You – everybody knows that
Maybe Panpan has found something of real interest/use…..
Jeez, what a joke. Bucket chemistry at its worst.
You’ll find much better science in the average meth lab.
”Phytoplankton are the main suppliers of polyunsaturated fatty acids in aquatic ecosystems. According to the study, the less nutritious phytoplankton that result from browning and warmer water ”
Does that mean that in areas that around say 2 degrees C warmer and with higher rainfall (closer to the equator) are less nutritious than in cooler zones?
I just can’t understand how nature can cope.
This study is a joke, established by a simple truth. The hot parts of the planet, that have been far hotter than the rest of the planet, did not experience this doom BS.
If it were true, they would only need visit and observer in those places and make empirically supported assertions.
Instead they made their own system and no doubt made changes that don’t happen in nature and in an extremely short time period compared to 100 years of alleged slow change over time because of future “predicted” warming.
This is a study method akin to putting corals in acidic water, it kills them, yet if you slowly change the pH to the same reasonably expected pH level over a 100 period, those corals would adapt (exactly how much I don’t know), but the outcome would be drastically different.
It’s the same with this study, not nature, a controlled system where it seems to me the scientists set out wanting to come to this conclusion, and building a study around that. (How can we make this system do what we want it to do?) and they did just that.
This is not science, it’s advocacy
I wonder how they explain how life functioned when the earth was several degrees warmer than now and it been that way for most of the history of the earth. Are they that ill informed?
“We changed the water contents of some barrels and tried to conclude what would happen to entire river systems. We try to do science at Dartmouth but we’re not as good at it as we are at keg parties.”
Simulations? So, no facts just a bunch of made up crap and leftarded lies.
Everything I’ve read about warmings all flora and fauna increased and then decreased as cooling came. With warming there is more tropical rain that floods into water bodies and includes snow/ice melts from the colder parts that brings nutrients to the flora and fauna. These people are nut cases.
Blah blah blah… the earth has been much warmer and had much more CO2 in the past. Life will adapt, even if there is one shred of truth in this paper, which itself is highly questionable.
Chinese scientist pushing global warming. Unsurprised.