How deep-ocean vents fuel massive phytoplankton blooms

More “settled science” of the carbon cycle~ctm

Stanford study shows how hydrothermal vents fuel massive phytoplankton blooms — and possible hotspots for carbon storage

Stanford’s School of Earth, Energy & Environmental Sciences

Researchers at Stanford University say they have found an aquatic highway that lets nutrients from Earth’s belly sweep up to surface waters off the coast of Antarctica and stimulate explosive growth of microscopic ocean algae.

Their study, published June 5 in the journal Nature Communications, suggests that hydrothermal vents – openings in the seafloor that gush scorching hot streams of mineral-rich fluid – may affect life near the ocean’s surface and the global carbon cycle more than previously thought.

Mathieu Ardyna, a postdoctoral scholar and the study’s lead author, said the research provides the first observed evidence of iron from the Southern Ocean’s depths turning normally anemic surface waters into hotspots for phytoplankton – the tiny algae that sustain the marine food web, pull heat-trapping carbon dioxide out of the air and produce a huge amount of the oxygen we breathe. “Our study shows that iron from hydrothermal vents can well up, travel across hundreds of miles of open ocean and allow phytoplankton to thrive in some very unexpected places,” he said.

Kevin Arrigo, a professor of Earth system science and senior author of the paper, called the findings “important because they show how intimately linked the deep ocean and surface ocean can be.”

Mysterious blooms

Phytoplankton need iron to thrive, and that limits their abundance in vast swaths of the ocean where concentrations of the nutrient are low. But when conditions are right, phytoplankton can also grow explosively, blooming across thousands of square miles in a matter of days.

That’s what Ardyna noticed recently as he looked at data recorded in 2014 and 2015 by a fleet of floating robots outfitted with optical sensors in the Southern Ocean. More than 1,300 miles off the coast of Antarctica and 1,400 miles from the African continent, two unexpectedly large blooms cropped up in an area known for severe iron shortages and low concentrations of chlorophyll, an indicator of phytoplankton populations.

Massive blooms in this region could only be possible with an influx of iron. Ardyna and Arrigo quickly ruled out the ocean’s most common sources, including continental shelves, melting sea ice and atmospheric dust, which were simply too far away to have much influence.

That led them to suspect that the nutrient must be welling up from below, possibly from a string of hydrothermal vents that dot a mid-ocean ridge 750 miles from where the massive blooms had inexplicably appeared. To help test their hypothesis, they recruited an international team of collaborators specialized in various aspects of oceanography and modeling.

“It has long been known that hydrothermal vents create unique and profound oases of life,” Ardyna said. Until recently, scientists generally believed those nourishing effects remained fairly local. But a growing amount of evidence from computer simulations of ocean dynamics has hinted that iron and other life-sustaining elements spewed from hydrothermal vents may in fact fuel planktonic blooms over much wider areas.

However, direct measurements have been lacking.

In the Southern Ocean, that’s partly due to the remote location, extreme cold and rough seas, which make it difficult to study up close or collect accurate data. “Your sensors have to be in the right place at the right time to see these blooms,” Ardyna said. “Satellites can underestimate intensity or miss them altogether because of bad coverage or strong mixing of the water column, which pushes phytoplankton down too deep for satellites to see.”

Clues from space, floating robots

To track the flow of particles from the vents on the mid-ocean ridge, the scientists analyzed data from satellites measuring chlorophyll and from autonomous, sensor-laden buoys known as Argo floats. As they dive and drift along ocean currents, some of these buoys detect chlorophyll and other proxies for phytoplankton biomass. “The floats give us precious and unique data, covering a large section of the water column down to 1,000 meters deep during an entire annual cycle,” Ardyna said.

The scientists couldn’t directly measure iron in the water, but instead analyzed measurements of helium collected by scientific cruises in the 1990s. The presence of helium signals waters influenced by hydrothermal vents, which funnel large amounts of primordial helium from beneath Earth’s crust.

The chlorophyll, phytoplankton and helium data suggest that a powerful current circling Antarctica grabs nutrients rising up from vents. Two turbulent, fast-moving branches of the current then shuttle the nutrients eastward for a month or two before serving them like a banquet to undernourished phytoplankton. Together with the arrival of spring sunshine that phytoplankton need for photosynthesis, the delivery triggers a massive bloom that can likely absorb and store significant amounts of carbon from the atmosphere, said Arrigo, who is also the Donald and Donald M. Steel Professor in Earth Sciences.

Over time, the blooms drift eastward toward the current racing around Antarctica and fade as sea creatures devour them. “We suspect these hotspots are either consumed or exported to deep waters,” Ardyna said.

Each bloom lasts little more than a month, but the mechanisms that trigger them are likely to be more common in the global ocean than scientists previously suspected.

“Hydrothermal vents are scattered all over the ocean floor,” Ardyna said. Knowing about the pathways that bring their nutrients up to surface waters will help researchers make more accurate calculations about the flow of carbon in the world’s oceans. “Much remains to be done to reveal other potential hotspots and quantify how this mechanism is altering the carbon cycle.”


From EurekAlert!


39 thoughts on “How deep-ocean vents fuel massive phytoplankton blooms

  1. This is another discovery about the wonderfull world.
    That shows that the consensus is correct.
    The Science is all agreed , or is that with out the A.
    This finding is true research.
    I await the spin.

  2. I didn’t know hydrothermal vents were ‘scattered all over the sea floor’ as claimed here by Ardyna? I thought they were concentrated along spreading ridges, so should not be so difficult to find?

    • Obviously, the vents are Scattered all along the sea floor in proxcimity to deep sea ridging/crustal spreading areas

    • Hydrothermal vents were once thought quite rare. Turns out they are found most especially along the largest geological feature on the planet, the mid-ocean ridge. Get a good map of the world’s oceans and see for yourself. Somewhere I have the numbers of vents already identified and those author’s believe the count had just become. Heard one number that said that in one stretch of mid-ocean ridge there was one thermal vent per every two to twenty kilometers.

      Several years ago I had an email debate with folks at one of the universities in Oregon who claimed to be studying thermal vents. They claimed that thermal vents were rare and had little if any influence on the ocean’s “climate.” I sent them some of the latest numbers that had just been published. That was the last email in the discussion.

      I know a group of vents off the southern tip of South America being studied flowed as much water as the Amazon River.

  3. There’s nothing like reading some settled science that nobody knew before, just before taking breakfast in England.

  4. “Much remains to be done to reveal other potential hotspots and quantify how this mechanism is altering the carbon cycle.”

    What a moronic comment. They discovered something that has been happening for billions of years and say it’s altering the carbon cycle?

    • “S what I was thinking. Next time someone tries to blame it on man made climate change, I feel like telling them to put a plug in their hydrothermal vent. 😉

      • Our hydrothermal vents are quite small and won’t require a very big plug. You may encounter resistance, however.

    • Interesting article. What else is dispersed into the oceans by these vents (which have always been in existence and might even have been the source for our DNA)? I do feel for these researchers, having to include some nonsense about AGW to ensure their work gets published. It is a sad world.

      Interestingly, I can recommend ‘Chernobyl’ on SKY(?). The way the ignorant party and KGB members (as portrayed) treat scientists is reminiscent of the political class today. Get a few ‘yes-men’ on side and proclaim that the science is settled because 97% (they couldn’t even get 100%!) say it is. Time to fight back and expunge these imbeciles.

    • They discovered something that has been happening for billions of years and say it’s altering the carbon cycle?

      They obviously mean it affects our understanding of the carbon cycle. The effects of the biosphere on the carbon cycle have been a source of surprises before. In the 1990s scientists could not explain where CO2 was going so they talked a lot about the missing sink.

  5. The planet appears to be a very complicated place.

    Does anyone know what happened to those experiments with seeding the ocean surface with iron particles to grow plankton?

    • Hi Phillip,
      do you walk around naked in winter or do you put some cloths on to trap your body’s

  6. Iron fertilization could restore the worlds fisheries and gradually expand them into dead zones if implemented. I’ve never seen any negative impacts reported but governments and environmentalists are against it.

    • A possible negative impact of iron fertilisation: It could accelerate the take-up of CO2 from the atmosphere, eventually depositing it on the sea-floor, and thus depriving the atmosphere of much-needed CO2. One of the things that concerns me is the high rate at which the ocean is absorbing our “excess” CO2. I fear that when we do desperately need more atmospheric CO2, it will be difficult to overcome the ocean’s appetite for it.

      • I suspect that there is a considerable quantity of liquid CO2 coming from those vents, both the hot ones and the cold one.

  7. Possible negative feedback.
    •Increased polar temperatures leads to increased glacial calving.
    •Leads to increased scraping of soil into the oceans.
    •Leads to increased enrichment of the oceans with iron.
    •Leads to phytoplankton blooms.
    •Leads to increased CO2 absorption and emissions of DMS.
    •Leads to more clouds and decreased polar temperatures.

    On another matter, I predicted this effect off hydrothermal vents in a comment on this blog years ago. Wait half a decade and this comment will be researched too.

    • Loren – “Is the helium primordial or is it alpha particles from nuclear decay?

      from the article “The presence of helium signals waters influenced by hydrothermal vents, which funnel large amounts of primordial helium from beneath Earth’s crust.”

      Although one would assume our fairly radioactive earth would be generating de rigueur.

  8. “they have found an aquatic highway” “nutrients from Earth’s belly” “gush scorching hot streams of mineral-rich fluid” “serving them like a banquet to undernourished phytoplankton”

    Save us from writers who get carried away by their own verbosity.

    a growing amount of evidence from computer simulations

    Save us from model output posing as data

  9. Next thing you know they will discover hydrothermal vent activity is not static across geologic time.

    • or tie solar activity to geologic mechanisms that fuel vents, thus providing the elusive connection to the Sun and Climate.

  10. Very interesting and believable. Pity they had to drag the inevitable CO2 hysterical Meme into it.
    Have long been of the opinion that what is happening beneath our feet is very relevant to our climate; but so far we are barely touching on understanding it.
    Lots of energy and tectonics popping up in various places just to confuse the calculations.

  11. Seeding the ocean with steel wool was tried many years ago
    and found to be very successful. It was known as the “Geritol
    Solution”. The plankton bloom was soo large that the person
    in charge of the experiment said,” If you give me a tanker load
    of steel wool, I’ll give you an Ice Age.”

    I think that as a solution to the “excess” CO2 problem, the
    “Geritol Solution” was too cheap and inexpensive and did not
    provide the pathway to global governance that is the actual
    goal of the watermelons.

    The thermal vents do, in fact, introduce many minerals to
    the oceans, and the fact that the life at the vents is powered
    by hydrocarbons lead me to the hypothesis that upland top soil
    is also powered by hydrocarbons.

    I subsequently devised a test and proved the theory to
    be correct.

  12. I’d be interested in any thoughts about the newly-discovered relationship between plankton blooms and hydrothermal vents and possible correlations to solar cycles and/or other gravitationally significant events in the solar system.

    The cyclical Venus-Earth-Jupiter alignment and solar activity is highly correlated and a recent paper about the solar dynamo establishes a possible mechanism.

    Paper here:

    At least one legitimate study I could find noted a weak but statistically significant correlation between cycles of earthquake and volcanic activity and the 11-year solar cycle, possibly affected by the same planetary gravitational perturbations.

    Apparently undersea volcanic activity and hydrothermal vents are difficult to study, though it is suggested that the majority of volcanic activity on earth is under the oceans. I’d be interested to know if anyone is exploring the possibility that gravitational influences in the solar system affect plankton blooms. Does anyone know of a study?

    • In answer to Skinterp 6 – 06 1 18 :
      look for Irina CHARVATOVA’s paper related to the irregular orbits of the sun and the influence they have on geologic events on Earth.
      (sorry no more precise reference)

  13. For some years now I have been trying to interest anyone with a knowledge of biomass calculations to do a back of the envelop estimate of the effect of whaling over the last three centuries on phytoplankton and zooplankton masses. Put simplistically whales eat zooplankton, zooplankton eat phytoplankton which are probably the largest carbon sink in the world. Did whaling influence the ecological balance to an extent that it had some effect on Atmospheric CO2. Accurate historical records of numbers of whales killed are available and the biomass was huge. Just a thought.

  14. God has created this world with a lot of internal checks and balances. Mankind is foolish to think we have the power of God to impact His world. Only a nuclear holocaust would have that impact and that might be the time for Him to say “I am stepping and taking over. Time for you fools to my power!”

  15. The ‘normal’ rules for phase equilibria do not fully apply with dissolution of CO2 in the oceans because of the chemical reactions that take place removing or sequestering the dissolved gas from the ‘equilibrium zone’. As can be seen an atmospheric pressure of 175 atmospheres would be required to account for the imbalance. Also sequestration would account for the low residence time of CO2 in the atmosphere (5-7 years):
    CO2- Water Solubility
    Henry’s-law constant H for CO2-water solutions is 1.42×10^3 atm/mole fraction at 20 C (10). Using simple Henry’s-law solubilities (p=H*x), the oceans should hold only 30% of the 2,900 giga tonnes of the atmospheric CO2 at equilibrium, but the actual figure is >50 times this amount. In fact, for an ideal vapour-liquid equilibrium system obeying Raoult’s law, an atmospheric pressure of 175 atmospheres would be required to contain this colossal amount (50*2,900=145,000 giga tonnes) of CO2 in the oceans. The majority share of CO2 is taken up by the oceans competing with the biosphere’s CO2 requirements for plant growth and food supply. Non-ideality accounts for its large solubility in water and clearly it is sequestered and fixed by chemical and biological reactions. They involve the formation of carbonate rocks and phytoplankton growth through photosynthesis. The reactions remove dissolved CO2 from the equilbrium equation, driving it to the right, thereby giving the oceans a near limitless ability to absorb CO2.

Comments are closed.