The Invisible Ocean Engine That Controls Earth’s Climate

1:00:00 Every year the ocean removes billions of tons of carbon dioxide from the atmosphere Most people assume that this happens because of whales, mangroves or seagrass But the biggest carbon capture system on Earth is microscopic. It is powered by microbes Invisible organisms drifting in the water column quietly regulate the Earth's climate This is the how to protect the ocean your weekly ocean news update if you care about staying informed on the ocean Every weekday hit that follow button right now. So you don't miss tomorrow's story Alright, let's just talk about it for a second ocean microbes help regulate the global climate by capturing carbon and Transporting it into the deep ocean. This process is known as the biological carbon pump without this system Scientists estimate atmospheric co2 concentrations would be roughly 50% higher than they are today Let's think about that 50% higher than they are today. The ocean does not simply absorb carbon like a sponge life in the ocean actively moves carbon from the atmosphere to the deep sea and Microbes drive that system. So the key question here is how do organisms Smaller than a grain of sand help regulate the entire planet's climate. Here's the problem Let's be honest climate change is accelerating human activities have dramatically increased atmospheric carbon dioxide Anybody tells you differently is absolutely wrong today co2 concentrations have exceeded 420 parts per million the highest levels seen in the last three million years

1:01:31 The ocean helps buffer the planet from this rapid increase Scientists estimate that the ocean absorbs about 25 to 30 percent of the co2 humans emit each year This buffer effect slows climate change without the ocean absorbing carbon Earth's climate would be warming significantly faster than it is already But the ocean doesn't simply absorb carbon passively it's not just sitting there as carbon dioxide floats above the water and just kind of absorbs it a large portion of the carbon is moved into deeper waters through biological processes driven by microbes to hear some of the science of people research on the Biological carbon pump. It's one of the most important processes regulating there's climate So there's a lot of research on it step one begins with phytoplankton This microscopic algae live near the ocean surface where sunlight penetrates the water like plants on land And phytoplankton use photosynthesis to convert carbon dioxide into organic carbon Scientists estimate that marine phytoplankton produce roughly half of the oxygen of the earth and fix about 50 gigatons of carbon annually comparable to all terrestrial plants combined once phytoplankton converts carbon into biomass the carbon begins moving through the food web zooplankton grays on phytoplankton fish consume zooplankton But the key step in the carbon pump happens when organic matter begins sinking this happens through several pathways one We call marine snow particles of dead phytoplankton fecal pellets from zooplankton and fragments of organic material clumped together into drifting aggregates known as marine snow These particles slowly sink through the water column some sink hundreds of

1:03:02 thousands of meters into the deep Microbes colonize these particles as they sink they break down the organic material Transforming it chemically some carbon is recycled back into the surface waters But a fraction continues sinking deeper when carbon reaches waters below a thousand meters it can remain isolated From the atmosphere for hundreds of thousands of years Globally scientists estimate the biological carbon pump transfers about 10 gigatons of carbon per year from the surface waters towards the deep of the ocean That is a massive climate regulating process driven largely by microscopic organisms Let's talk about cyanobacteria amongst the most important carbon capturing microbes in the ocean are cyanobacteria These organisms are photosynthetic bacteria that evolved more than 2.5 billion years ago And we're responsible for producing much of the oxygen that transformed the Earth's early atmosphere Two of the most abundant species in the ocean are chlorochlorococcus and Sinocorococcus sorry about the pronunciation of trouble reading these chlorochlorococcus is especially remarkable It is believed to be the most abundant photosynthetic organism on Earth scientists estimate there may be around three Octillion cells globally meaning a three followed by 27 zeros in some tropical ocean regions a single millimeter of seawater may contain a hundred thousand or more chlorochlorococcus cells these organisms capture carbon dioxide using sunlight and Convert it into organic carbon although each cell is tiny their collective activity is enormous together

1:04:34 Plurico caucus and sinoco caucus contribute a significant portion of photosynthesis They form a foundation of many marine food webs supporting everything from zooplankton to large fish in many parts of the open ocean Nutrients are scarce these microbes dominate primary production their activity is a major component of the biological carbon pump Climate change has the potential to disrupt the microbial systems that regulate carbon in the ocean One major risk is ocean warming warmer water tends to increase stratification meaning the ocean becomes more layered surface waters warm and become less dense reducing mixing with colder nutrient rich water Phytoplankton rely on nutrients such as nitrogen phosphorus and iron that often come from deeper waters When mixing weakens fewer nutrients reach the surface. This can reduce phytoplankton productivity Another risk is change in plankton community composition climate-driven warming often favors smaller phytoplankton species including tiny Pecoplankton smaller cells tend to sink more slowly than larger plankton like diatoms Diatoms have silica cells that make them heavier and they sink a lot quicker when they die If the ocean shifts towards smaller plankton communities less carbon may be exported to deeper waters This could weaken the biological carbon pump A large globe analysis found that warming oceans may reduce the efficiency of carbon export in some regions Which means that more carbon will remain near the surface and eventually return to the atmosphere So what does success look like when we're

1:06:04 talking about protecting the biological carbon pump? Well, this will require protecting the conditions that allow microbial ecosystems to function one major factor is nutrient balance So excess nutrient pollution from agriculture can trigger harmful algal blooms that disrupt marine ecosystems So think about everything that's happening in florida when florida the state of florida moved to best practices in terms of regulating nutrients That come out of big sugar and it went into lake oak ochibi. I think that's how you pronounce it I always forget how you pronounce it and they go into those two rivers one goes to the atlantic one goes to the gulf A lot of times when you have excess nutrients in those rivers and the heat kind of heats it up at the right time All those nutrients and phytoplankton go into the ocean in a heavy heavy concentration You get cyanobacteria you get all this other algal blooms and then you get these red tides that we discussed in yesterday's episode Where you have this mixing of you know The right amount of nutrients the right amount of wind the right amount of currents driven in the right way and the right amount of dinoflagellates which cause red tide and can kill a lot of other species and cause a nasty smell and just the smothering of reefs as well as Sea grasses that can help feed the entire food web and so not having being able to balance these nutrients and being able to monitor These nutrients is really important So when governments and policymakers try to go to best practices, these companies are not using best practices They're just using whatever they want to use. It's a ploy. That's how they get it. So at the same time Some open ocean regions are nutrient limited understanding. This balance is

1:07:35 critical for managing coastal ecosystems So another key strategy is long-term plankton monitoring which can be really easy to do programs Like the continuous plankton recorder survey which has been operating since the 1930s helped scientists track changes in plankton communities across the entire ocean Basins these long-term data sets allow researchers to detect climate driven shifts in ocean ecosystems Finally scientists are increasingly working to incorporate microbial processes into global climate models for decades many climate models simplified ocean biology But new research is improving how models represent microbial food webs and carbon export processes Understanding microbes is essential if we want to predict how the ocean will regulate climate in the future If you love the way this show breaks down science information and you're learning from this Please consider following the podcast by hitting that follow button and of course share it to someone that you think will benefit from this So let's look into the final thoughts when we imagine climate solutions We often picture forests renewable energy and carbon capture technology But the ocean is already running one of the most powerful carbon capture systems on earth It's been doing so for millions of years and it is powered by organisms too small to see Tomorrow we're going to look at another microbial ability how microbes can help clean pollution from the ocean That's it for today's episode. If you have any questions or comments, please Let me know by going to speak up for blue.com forward slash feedback that speak up for blue.com Forward slash feedback. You can leave a voicemail or you can just type some stuff

1:09:07 out questions comments Whatever you want to do feedback. I would love to hear it Like I always say this is a podcast where I start the conversation But i'd love for you to continue that conversation and let's talk oceans I want to thank you for joining me on today's episode of the how to protect the ocean podcast. Have a great day We'll talk to you next time and happy conservation