New factor in the carbon cycle of the Southern Ocean identified

GEOMAR scientists show that besides iron, manganese can also limit the growth of photosynthesis-performing plankton


Research News


The term plankton describes usually very small organisms that drift with the currents in the seas and oceans. Despite their small size, they play an important role for our planet due to their immense quantity. Photosynthesizing plankton, known as phytoplankton, for example, produce half of the oxygen in the atmosphere while binding huge amounts of carbon dioxide (CO2). Since the Southern Ocean around Antarctica is very rich in nutrients, phytoplankton can thrive there. It is therefore a key region for controlling atmospheric CO2 concentrations.

As other nutrients are abundant, scientists have so far assumed that the amount of the available “micronutrient” iron determines how well phytoplankton thrives or not in the Southern Ocean. Researchers from GEOMAR Helmholtz Centre for Ocean Research Kiel and the UK’s National Oceanography Center have now published a study in the international journal Nature Communications showing for the first time that in some areas of the Southern Ocean, manganese, not iron, is the limiting factor for phytoplankton growth.

“This is an important finding for our ability to assess future changes, but also to better understand phytoplankton in the past,” says Dr. Thomas J. Browning of GEOMAR, lead author of the study.

Earlier research suggests that greater phytoplankton growth in the Southern Ocean was a key contributor to the onset of the ice ages over the past 2.58 million years. More phytoplankton was able to bind more CO2, which was removed from the atmosphere. As a result, average global temperatures further declined. “So it’s critical that we understand exactly what processes regulate phytoplankton growth in the Southern Ocean,” Dr. Browning points out.

Indeed, along with iron, manganese is another essential “micronutrient” required by every photosynthetic organism, from algae to oak trees. In most of the ocean, however, enough manganese is available to phytoplankton that it does not limit its growth.

Measurements in remote regions of the Southern Ocean, on the other hand, have shown much lower manganese concentrations. During an expedition on the British research vessel RRS JAMES CLARK ROSS through the Drake Passage between Tierra del Fuego and the Antarctic Peninsula in November 2018, Dr. Browning and his team took water samples. While still on board, they used these water samples and the phytoplankton they contained to conduct experiments on which nutrients affect growth and which do not.

“In doing so, we were able to demonstrate for the first time a manganese limitation for phytoplankton growth in the center of Drake Passage. Closer to shore, iron was the limiting factor, as expected,” Dr. Browning reports.

After the expedition, the team used additional model calculations to assess the implications of the experimental results. Among other things, they found that manganese limitation may have been even more widespread during the ice ages than it is today. “This would make this previously unaccounted for factor a central part of understanding the ice ages,” says Dr. Browning.

However, because this is the first record in a specific region of the Southern Ocean, further research is needed to better understand the geographic extent and timing of manganese limitation in the Southern Ocean. “We also still need to study what factors control manganese concentrations in seawater and how phytoplankton adapt to manganese scarcity. All of this is critical to building more accurate models of how the Earth system works,” Thomas Browning concludes.


From EurekAlert!

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Ron Long
February 10, 2021 2:57 am

Somewhere there is a manganese control knob that determines, with impressive regularity, when the entire earth is in the intra-glacial or inter-glacial phase of the current Ice Age we are in? So hard to imagine I won’t even try. Next?

Krishna Gans
February 10, 2021 3:03 am

Deeper research, further studies, where are the funds ? 😀
Is there anything not related to what change of climate ever ?

Peta of Newark
February 10, 2021 3:06 am

Good start…..
“”Southern Ocean around Antarctica is very rich in nutrients“”

What are these nutrients and where did they come from?
Anyone round here who has ever read any of my ravings will know exactly where they came from and surely Shirley, must still be coming

It leads the Enquiring Minds to ponder, seeing as these nutriment sources are quite boisterous machinations and indeed rather hot (blows a kiss and waves to Zoe), if that might affect the amount of ice around Anataricica?

As far as plants and indeed critters go, pretty well half of everything mentioned on the Periodic Table is needed – in varying amounts ##

Then it gets a bit weird..
“”Closer to shore, iron was the limiting factor, as expected,” Dr. Browning reports””
Two probs here:
1) Why was it ‘as expected‘?
(We are dealing with CAGWCCAGAAWWW warming weirding so anything indeed can be expected, so real real prob)

2) Certainly I would have expected a lot of Iron to be just offshore.
Iron is precisely what makes all contemporary flood waters the colour(s) that they are (red, orange or yellow typically)
And dust storms.
Thus, where did all that Iron go?
I know I know, Iron is heavy and it sank, but why did it preferentially sink in the shallow water rather than the deep water?

Feeling a bit low because covid, climate whatever?
Take yourself down the nearest Agricultural merchant, look for something like this/these. We call them Rockies in this part of t’world Horses and cows like them.

But get a load of all them Nutriments!!!
Mash/crunch it up and apply liberally via your normal salt-pot to french-fries, crisps/chips, pasta, roz-biv & steaks, ribs, chops, veggies whatever etcetera

Not dissimilar to Trendy Himalayan Rock Salt but, its analysis is truly puny.
Pretty colour though.

We treat animals better than we treat each other or even ourselves much of the time.
While you’re there, pick up an agricultural size pack of Cod Liver Oil
On your return home, find a large shot-glass and keep one next t’other
Thus when the Climate Zombies ‘get a bit much’ or anything indeed gets-a-bit, you’ll find you have some Instant Acting Prozac that Actually Does Work.
OK ok, not instant instant = give it 60 minutes. tops. trust me, it does work.
Or just a general ‘wake-me-up’
Bit healthier than nicotine, coffee, MDMA or cocaine not least

February 10, 2021 3:16 am

“…more CO2, which was removed from the atmosphere. As a result, average global temperatures further declined.”
Wasn’t that BS disproven multiple times?
I still think these people are religious freaks trying to (de)terraform our planet in the hope their absent god/s will return to live amongst us again. They have this dogma about carbon in the atmosphere, and all other ideas are blasphemy.
Pathetic. Extremely dangerous to humankind, but pathetic.
Also, correlation does not causation imply…

Reply to  paranoid goy
February 10, 2021 3:37 am

Dang, p g,you beat me to it.

Reply to  paranoid goy
February 10, 2021 5:08 am

“…more CO2, which was removed from the atmosphere. As a result, average global temperatures further declined.”
Wasn’t that BS disproven multiple times?

Answer: Yes – disproved many times – as I recall, about 25 times in my Jan2020 paper, and there are even more disproofs – I just got tired of writing after ~25.

The ability to predict is the best objective measure of scientific competence. These climate doomsters have a perfect negative predictive track record – every very-scary climate prediction they have made in the past ~four decades has failed to happen.

“MacRae’s Maxim”:

There is a powerful logic that says that no rational person can be this wrong, this deliberately obtuse, for this long – that they must have a covert agenda. I made this point circa 2009, and that agenda is now fully exposed – it is the Marxist totalitarian “Great Reset” – “you will own nothing, and you’ll be happy!”
The proponents of both the very-scary Global Warming / Climate Change scam and the Covid-19 Lockdown scam know they are lying. Note also how many global “leaders” quickly linked the two scams, stating ”to solve one we have to solve the other”- utter nonsense, not even plausible enough to be specious.

January 10, 2020

Reply to  paranoid goy
February 10, 2021 7:48 am

The article states that during the last “ice age”, the manganese shortage was even more extreme. This would have meant that the plankton were removing less CO2 during an ice age. According to their theory of CO2 uber alles, that should have made the ice ages less extreme.

Reply to  MarkW
February 10, 2021 7:59 am

Hurmph! I don’t think they saw that one!
Allan above presents a precis on all the bulldust so far.

February 10, 2021 3:17 am

” ………. bind more CO2, which was removed from the atmosphere. As a result, average global temperature further declined.”

Link to that?

Krishna Gans
Reply to  Oldseadog
February 10, 2021 4:02 am

There isn’t. 😀

February 10, 2021 3:50 am

More phytoplankton was able to bind more CO2, which was removed from the atmosphere. As a result, average global temperatures further declined. 

In what way does reducing CO2 have any impact on surface temperature?

The surface temperature on Earth is thermostatically controlled without any influence from CO2.

A whole generation or even two generations have been completely led astray by this “Greenhouse Effect” nonsense. It will be remembered as one of the worst periods in scientific enquiry. So many resources wasted on religious dogma.

Eric Vieira
February 10, 2021 4:08 am

The effects of Mann-ganeese ?

February 10, 2021 4:24 am

This paper is another of those that assume that global temperature is controlled by CO2.

If you search WUWT, you find plenty of evidence that CO2 lags temperature. example

If you google for CO2 lags temperature, you get mostly hits which claim to debunk the temporal relationship between CO2 and temperature. Lysenko is alive and living at the Helmholtz Center for Ocean Research, or somewhere like that.

Jon Scott
February 10, 2021 6:11 am

I find the small amount of Carbon Cycle discussion very odd because geological history which is CRITICAL to it is NEVER discussed. How can anyone perform any science if they assume as do all the climatista goons that climate did not change until yesterday? The starting point has to be what has happened over at least the past 500 million years and in particular acknowledged the fact that it is out of sync and has been for 160 million years. There is your starting point.

Joel O'Bryan
Reply to  Jon Scott
February 10, 2021 1:04 pm

Michael Crichton explained why Western-style Environmentalism, and environmentalism that Climate Change is part of, is a religion akin to the belief in the Earth was a biblical “Garden of Eden” before mankind came along with SUVs and digging up coal to burn and despoiled it with carbon sins.

February 10, 2021 7:33 am

Carbon accountancy is one of the most pointless topics of climate research, and there’s stiff competition for that accolade.

February 10, 2021 7:49 am

ah the Drake Passage

enjoy it while it lasts

suspect the great geo-engineering project of the 2100s and 2200s will be to partially dam the southern circumpolar flow, altering global climate enough to keep the interglacial going through the next few obliquity cycles, and incidentally generating enough hydropower to begin terraforming the tops of the Antarctic ice sheets

there’s no life like dome life

Reply to  TallDave
February 10, 2021 12:52 pm

Don’t give them any ideas!😟

joe Lynch
Reply to  TallDave
February 12, 2021 2:02 am

Ah yes, the green green grass of Dome, where the buffalo roam and the deer and the antelope play{ed}….until evil Hoomans came along and changed everything!

H. D. Hoese
February 10, 2021 8:15 am

I’m locked out of my library by some university administrator lacking some essential brain element, so can’t check on this and later papers, but are these guys way behind? It has long been known that various elements can become limiting. Manganese is one that can be concentrated by organisms and is not very abundant. Have read that the Drake Passage is a very active place. Harvey, H. W. 1939. Substances controlling the growth of a diatom. Journal Marine Biological Association of the United Kingdom.23:499-520 is referenced as manganese “influencing the growth of a diatom. ”

Clyde Spencer
Reply to  H. D. Hoese
February 10, 2021 10:17 am

“Manganese … is not very abundant.”

Except as nodules on the abyssal plains. And, perhaps, the remnants of subducted abyssal plains.

February 10, 2021 10:50 am

Manganese (Mn) micro-molar level insufficiency during a plankton “lag” cell cycle stalls it in that paused state & this has relevance for functioning colony numbers. Closer to shore Mn bearing run-off is usually more Mn enriched than in open water, so iron sufficiency becomes more relevant.

There is variability of Mn in different bodies of water & seasonal Mn variability. It also takes light & not just Mn for the resumption of a cell cycle beyond it’s lag phase.

Joel O'Bryan
February 10, 2021 12:40 pm

“Photosynthesizing plankton, known as phytoplankton, for example, produce half of the oxygen in the atmosphere while binding huge amounts of carbon dioxide (CO2). “

Someone a Helmhotlz needs to go back to their Biochemistry textbook and brush up on photosynthesis. The chemically correct word would be “reduce”. Chelation molecules (like EDTA) can “bind” metal cations like Mg++, etc. and then release them under altered chemical conditions. Semantics in science matter becasue they carry underlying meaning of our knowledge.

Photosynthesis does not “bind” CO2. It uses the reducing power produced from the light harvesting reactions to chemically reduce the carbon atom in CO2 molecule into a growing sugar ring whereby the oxygens are also incorporated into the sugar. The food we eat literally is reduced CO2 (carbon gains electrons).

Peter Fraser
February 10, 2021 12:46 pm

When studying phytoplankton in the Southern Ocean scientists continue to ignore the elephant which is no longer in the room which is the huge loss of biomass from commercial whaling during the last 150 years. Whales both fertilise phytoplankton and eat zooplankton. Zooplankton live on phytoplankton. The loss of a huge proportion of the whale biomass one must assume had large influence on ocean ecosystems

Joel O'Bryan
Reply to  Peter Fraser
February 10, 2021 1:15 pm

The development of technology of petroleum production Saved the Whales in the late 19th Century from further hunting as they grew scarcer.
Humanity is going to get the energy we need because the knowledge and technology we have that uses that compact chemical energy cannot be “un-invented.”

We can get the energy we need in free, affluent, educated democratic societies that try to care for the environment and minimize total impacts, or we can adopt totalitarian political structures where the masses are forced to subsistence living that do not care about the environment, and the elites care only about holding all political power.

Joel O'Bryan
February 10, 2021 12:59 pm

I would posit that the reason Iron is not the limiting cation in the Drake Passage is the upwelling of the THC current and deep ocean volcanic activity (magma vents and black smokers) brings iron to that area.

Black smokers:

A venting black smoker emits jets of particle-laden fluids. The particles are predominantly very fine-grained sulfide minerals formed when the hot hydrothermal fluids mix with near-freezing seawater. These minerals solidify as they cool, forming chimney-like structures. “Black smokers” are chimneys formed from deposits of iron sulfide, which is black. “White smokers” are chimneys formed from deposits of barium, calcium, and silicon, which are white.

Also see;

Screen Shot 2021-02-10 at 1.58.01 PM.png
Joel O'Bryan
Reply to  Joel O'Bryan
February 10, 2021 1:31 pm

The map above shows there are at least 3 known hydrothermal (smokers) fields in the Drake Passage area.

From 2012 PLoS Biology (open access):
The Discovery of New Deep-Sea Hydrothermal Vent Communities in the Southern Ocean and Implications for Biogeography

and from 2001,
Discovery of new hydrothermal vent sites in Bransfield Strait, Antarctica

The huge waves, storms and heavy seas typical in the Drake Passage makes exploring the seafloor in that area quite difficult. The Branfield Strait vent system is much more sheltered with the island chain to the north.

John Tillman
Reply to  Joel O'Bryan
February 11, 2021 3:40 pm

Many don’t appreciate the fact that the Pacific coast of Antarctica lies on the Ring of Fire.

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