the ocean can be a dark and mysterious place and the deeper you go the weirder it gets as a species we've only explored about 5% of the cold Dark Void that covers our planet and it just got even stranger 5,000 MERS below the surface in the pitch black a mysterious source of oxygen has just been discovered has the call of cthulu finally been answered probably not but the truth is much more perplexing and may change science forever and it was all discovered by accident back in 2013 Andrew Sweetman a researcher from the Scottish Association for
Marine Science noticed something strange on the ocean floor he was studying a region of marine ecosystems located between Hawaii and Mexico called The claran clipperton Zone a sea bed that is larger than the country of India as part of his research sweetman's team sent down machines designed to measure the oxygen levels within this environment once at the bottom these automated seaf Flor Landers sealed off sections of sea bed with cylinders about 22 cm square in size and measured how the concentrations of oxygen in the seawater changed over a period of several days from their previous
research in areas around the world Sweetman and his team expected to see a gradual decline in oxygen levels as organisms within the sea waterer consumed the oxygen through respiration the rate of consumption could be an indicator of the amount and health of marine microorganisms in the sample and could indicate the health of the seabed overall but on this particular trip something strange happened instead that Sweetman had never seen before the instruments showed that the sequestered water became richer in oxygen over time rather than being consumed something was producing oxygen this discovery of dark oxygen was
announced a couple of days ago what is happening here and what does it mean and why on Earth did they decide to call it dark oxygen these findings are really interesting so I want to cover how oxygen usually works in the deep sea what the researchers found and their leading theory as to what they think is causing it but first I have to thank today's video sponsor short form for viewers of this channel I think you've already clocked that I'm equally fascinated by space as approaches diffusion why bats are so weird and how to make
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my link in the description down below short form.com doben to get a free trial and 20% off your subscription thank you short form for sponsoring this channel now let's get into the video I want to start with how oxygen usually makes its way down into the deepest parts of our oceans almost all of Earth's oxygen is produced by photosynthesis carried out by Plants algae and certain types of bacteria you're likely already pretty familiar with this process it occurs in chloroplast within plant cells which contain a green pigment called Chlor chlorophyll this pigment captures sunlight splits
water and carbon dioxide and produces sugar and importantly for Life Like Us gaseous oxygen as a waste product oxygen produced on land is spread across the planet through atmospheric circulation but how it gets deep into the oceans is more complicated at the surface oxygen from the atmosphere can diffuse directly into the surface of water assisted by winds and the mixing effect that increases the water's surface area in the topmost layers water can also be filled with photosynthetic microorganisms that are producing oxygen directly into the water in fact some estimates indicate that phytoplankton alone which occur
in water produce around 50% of the entire planet's oxygen however sunlight entering the water can only ever travel down about 1,000 M into the ocean under perfect conditions but usually more like 200 M or so this means that photosynthesis and oxygen availability rapidly fall off Beyond this depth so how does oxygen reach reach deeper layers of water that mostly relies on the fact that gases dissolve better in cold water than warm water and that cold water is also denser than warmer water so it sinks this allows polar water to soak up and hold onto large
amounts of oxygen and then be drawn down to the ocean floor creating a convection current called the thermohaline circulation this drives a global conveyor belt moving oxygen rich Waters across the ocean floor over a surprisingly long and slow process circulating on time scales between 100 and a thousand years this provides a constant low level of oxygen to the ocean floor enabling life to thrive even if it does sometimes look a little weird this idea that oxygenated ecosystems are only possible through photosynthesis and that all other ecosystems are kind of Lucky to receive some of the
offshoot oxygen has been the foundation of how we understand why life has evolved the way it has on these systems and on Earth as a whole sweetman's discovery that actually there may be a source of oxygen on the ocean floor potentially could rewrite our understanding of what is possible on our [Music] planet initially when Sweetman and his team actually retrieved their data they actually thought that the sensors they were using were faulty because every study ever done in the deep sea has only ever seen oxygen being consumed assumed rather than produced they put the results
down simply to bad data and moved on with other experiments it wasn't until 8 years later in 2021 that Sweetman went on another research cruise and again found the same results for this experimental run however the researchers has used a different measurement method so now two independent approaches had produced data sets that both showed the same result it was at this point that Sweetman realized that for the last eight or 9 years he may have been ignoring this hugely groundbreaking process occurring 4,000 M down on the ocean floor further still the amount of oxygen being
produced wasn't insignificant the concentrations in these Chambers began to exceed the oxygen level normally observed in surface waters rich with photosynthetic organisms so what was actually going on here this is where a unique feature of the claran clipon Zone comes into play in this area of the Pacific the sea floor is covered with small rock-like clusters rich in metallic deposits called poly metallic nodules you may have heard of these clusters before they are the resources often targeted by Deep Sea mining companies as they full of valuable materials like Cobalt manganese and nickel critical for various
industries from battery technologies to consumer electronics these poly metallic nodules were unique to the Clarian clipon Zone that Sweetman was studying suggesting that these rocks may have an important role in September of 2023 Sweetman contacted his colleague France Gyer a professor of chemistry at Northwestern University to discuss possible explanations for this oxygen source the result of this work was the pair coined the term dark oxygen because like all good scientists when faced with a mysterious phenomena that can't be explained you just prefix it with dark Giga though did have experience investigating novel oxygen sources and
had previously found that under certain conditions salt water in the presence of rusted metal can generate small electric currents could it be that these metallic nodules were performing a simple form of electrolysis splitting water into its components of hydrogen and oxygen through some rudimentary form of naturally occurring battery to understand what was actually happening the team recreated the conditions found on the sea floor in a laboratory on board their ship the Searchers began by sterilizing their samples to remove possible oxygen producing organisms from the samples of nodules and seaf FL sediment to ensure that no
other sources of oxygen generation existed in their experimental equipment by enclosing the samples in airtight containers they monitored the oxygen levels over a period of several days consistent with their observations on the ocean floor the team observed again that the oxygen levels slowly increased in the containers despite no photosynthetic life being present interestingly oxygen levels increased to three times the background concentration ultimately then slowly plateauing after a few days to provide a deeper analysis the pair then shipped crates of samples to giger's laboratory at Northwestern University and what they found was shocking literally from the
surface of a single nodule the team measured voltages of up to 0.95 Volts for context here it takes about 1.5 of electricity about the same as a standard AA battery to split seawater through the process of electrolysis so here we have some kind of interesting facts starting to come together we have evidence of some voltage generation the oxygen produced in their experiment plateaus which could indicate that the energy that drives the splitting of these water molecules becomes somehow depleted so maybe the team is correct and that somehow there is a form of geological battery in
operation polymetallic nodules are pretty strange structures typically forming over millions of years as metals from seawater precipitate onto a nucleating point usually something like a fragment of shell a bone or a rock and most of the estimates that I've seen say they grow at a rate of 1 to 10 mm per million years in the paper they hypothesize that the dark oxygen production may have partly resulted from seawater electrolysis with the necessary energy coming from the potential difference between metal I ions within the nodular layers leading to an internal redistribution of electrons they go on
to say that the geob battery hypothesis is further supported by the link between the dark oxygen production rate and the average surface area of a nodule what does that mean that just means the bigger these nodules get the more oxygen they seem to produce this connection could be due to an increased abundance of anod and cathode sites or a greater abundance of high nickel or copper dendritic porous layers in little AR nodules however that kind of opens up more questions like why didn't this process deplete a long long time ago a battery in practice is
actually a very hard thing to get right I appreciate here that this is still very early work but this feels like kind of a weak argument to me because many mechanisms could be surface area dependent at the moment we just don't really know what is actually happening here one point I did find interesting though was that there was a theory put forward by the researchers that potentially the initially very very high oxygen production rate that ultimately then plateaued may have been related to the bow wave of the landing Vehicles removing sediments from the surface of
these nodules and exposing electrochromically active sites this again is kind of surprising to me and I'm not entirely sure that I'm convinced by that as an explanation in my mind the rate at which these nodules grow is so incredibly slow that the idea that sediment deposition or removal of that sediment is ultimately the rate limiting step just doesn't really feel that reasonable to me but as of yet we have very little further information we do know though that oxygen it looks like is being produced and actually that's a really awkward realization for the deep sea
mining companies that partly funded This research if we do find that these polymetric nodules provide essential sources of oxygen for deep sea life but potentially also for our planet as a whole then maybe mining these deposits for resources could turn out to be a really bad idea in response to this study Patrick DS a representative of the metals company one of these deepsea mining companies that funded the work said he has serious reservations about the findings adding that his own analysis suggests sweetman's results are due to oxygen contamination from external sources which would be very
convenient say if you were a mining company that didn't want its operations to ultimately be disturbed apparently a rebuttal article is on its from this group so we'll just have to wait and see however this is something we should take seriously back in 2016 marine biologists visited sites that were mined in the 1980s and found that not even bacteria had recovered in the mined areas whereas in unmined regions nearby marine life continued to flourish why such dead zones persist for decades is still kind of unknown however this should put a major asterisk onto strategies for
deep sea floor mining as the foral divers it on nodu rich areas is actually even higher than the most diverse tropical rainforests a deeper understanding of how these oxygen generation mechanisms work and if they are significant to oxygen levels on our planet either now or any time in our past could be influential to understanding not only how life evolved on our planet but also how we look out to our universe to determine if what we are seeing out there are actually signs of life if oxygen can can be created easily and commonly without the Need
For Life our studies looking for molecular oxygen on exoplanets might turn up nothing more than just a bunch of space rocks this is a really fascinating and deep topic and if you are interested in it we actually did a video very recently with literally one of the pioneers of research in this field looking for signs of alien life that are outl in the universe I'll leave a link somewhere or down in the description so you can find out more I want to know what you think about this breakthrough I think at the moment there are
very little credible other theories being put forward but I don't entirely believe this battery argument because the mechanics and complexity of actually making working batteries that don't instantaneously deplete themselves is pretty tricky to get right what else could be causing this tell me what you think in the comments down below do you agree with this Geo battery hypothesis personally like I said I'm not convinced if you guys really enjoyed this video and you'd like to support the channel more than you already are by watching feel free to check out our patreon page that we literally
just launched thank you as always for tuning in see you guys next week goodbye
