WEBVTT - BrainStuff Classics: How Do Nutrients Get into the World's Oceans?

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<v Speaker 1>Welcome to brain Stuff production of I Heart Radio. Hey

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<v Speaker 1>brain Stuff, I'm Lauren Vogel Bam, and this is another

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<v Speaker 1>classic brain Stuff episode. In this one, we dig into

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<v Speaker 1>how the life giving nutrients and Earth's oceans come from

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<v Speaker 1>a perhaps unlikely source, dust from deserts. Hey brain Stuff,

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<v Speaker 1>Lauren Vogel bomb Here. The Sahara Desert is a long

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<v Speaker 1>way from the Caribbean, but that doesn't matter. What happens

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<v Speaker 1>in Africa doesn't necessarily stay in Africa. Take dust, for instance,

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<v Speaker 1>The dirt on the ground in North Africa is dry

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<v Speaker 1>and the desert is windy. Every summer, dust from the

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<v Speaker 1>dunes of the world's largest desert pours into the atmosphere

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<v Speaker 1>over the North Atlantic to see the world's oceans with

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<v Speaker 1>nutrients that are sorely limited in many marine ecosystems, most

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<v Speaker 1>notably iron, which is essential to the growth of plants.

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<v Speaker 1>What happens to that dust after it leaves home can

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<v Speaker 1>be very good or very bad. It's sort of a crapshoot.

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<v Speaker 1>Nothing is stationary or permanent or simple on this wild

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<v Speaker 1>planet of ours. The major dust related pro the iron

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<v Speaker 1>that gives Saharan dust its rich red color, feeds the

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<v Speaker 1>phytoplankton in the Caribbean and along the coast of the

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<v Speaker 1>southeastern United States, which is important because you want to

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<v Speaker 1>know a big reason why you're breathing air right now phytoplankton.

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<v Speaker 1>We spoke with Jason west Ritch, a postdoctoral research scientist

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<v Speaker 1>in the University of George's Department of Microbiology. He said,

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<v Speaker 1>for a long time it's been assumed the tropical forests

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<v Speaker 1>of the world or the primary source of oxygen in

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<v Speaker 1>the atmosphere, but now it's more appreciated that the production

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<v Speaker 1>in the ocean acts as a second lung for the planet.

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<v Speaker 1>Phytoplankton photosynthesis is responsible for half of the oxygen and

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<v Speaker 1>also a substantial uptake of carbon dioxide on this planet.

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<v Speaker 1>Now for the dust related khan In a study, a

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<v Speaker 1>research team led by west Ritch found that phytoplankton isn't

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<v Speaker 1>the only organism in the Caribbean using the magic desert

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<v Speaker 1>dust bacteria. Notably, twelve different species of pathogenic bacteria from

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<v Speaker 1>the genus Fibrio use these nutrient infusions to create blooms

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<v Speaker 1>of their own. Vibrio bacteria are pretty ubiquitous in the

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<v Speaker 1>world's oceans, but there are freshwater species too. You've probably

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<v Speaker 1>heard of cholera, the disease brought to you by the

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<v Speaker 1>freshwater Vibrio colare, which infects millions of people worldwide each year,

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<v Speaker 1>especially in developing countries. A color outbreak after the earthquake

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<v Speaker 1>in Haiti killed an estimated ten thousand people, and in Yemen,

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<v Speaker 1>an ongoing cholera epidemic has infected over a million people

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<v Speaker 1>and killed two thousand and counting. Another fibrio, the flesh

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<v Speaker 1>eating marine Vibrio volnificus, is also deadly to humans. It

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<v Speaker 1>can gain entry through an abrasion or puncture wound, such

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<v Speaker 1>as a fish hook, leading to severe infection, especially for

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<v Speaker 1>immunocompromised individuals. Marine Fibrio species also play a role in

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<v Speaker 1>many diseases of ocean organisms. You know how, you're not

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<v Speaker 1>supposed to eat shellfish from some places during the summer.

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<v Speaker 1>That's because there are more Vibrio in the water when

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<v Speaker 1>it's warmer and filter feeding shellfish accumulate two species of

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<v Speaker 1>Vibrio in their meat, which caused the majority of seafood

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<v Speaker 1>related sickness and death in the United States. Other Vibrio

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<v Speaker 1>species are known to be associated with diseased coral that

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<v Speaker 1>are already facing so many environmental stressors. Vibrio disease and

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<v Speaker 1>mortality has even placed economic strain on the fishing and

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<v Speaker 1>shrimp farming industries. West Ritch said, understanding what drives fluctuation

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<v Speaker 1>of Vibrio in the environment can help to inform our

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<v Speaker 1>predictive potential of when to expect increased disease risk in

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<v Speaker 1>humans and other marine organisms. For example, we can track

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<v Speaker 1>sahir and dust by satellite over the typical five day

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<v Speaker 1>transit across the Atlantic before it arrives in US coastal waters,

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<v Speaker 1>allowing us to warn a swimmer, scuba diver, or fisherman

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<v Speaker 1>that there might be a peak and potentially harmful Vibrio

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<v Speaker 1>in surface water in the Keys. Because Vibrio are one

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<v Speaker 1>of the most researched marine bacterial genuses, researchers already know

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<v Speaker 1>a lot about their biology, ecology, physiology, and genetics. And

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<v Speaker 1>because they can reproduce so quickly under the right nutrient conditions,

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<v Speaker 1>one of its species has a population doubling time of

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<v Speaker 1>just ten minutes. Vibrio make a great model to probe

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<v Speaker 1>the lifestyle strategy of an organism capable of quickly blooming

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<v Speaker 1>when the nutrient circumstances are right next Westritch and his

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<v Speaker 1>colleagues will be working to better understand the role of

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<v Speaker 1>Vibrio blooms on marine iron availability to see if they're

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<v Speaker 1>competing with phytoplankton for that sweet, sweet iron dust. Today's

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<v Speaker 1>episode is based on the article Saharan Dust, The Good,

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<v Speaker 1>the Bad, and the Gritty on houst works dot Com,

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<v Speaker 1>written by Jesslin Shields. Brainstuffs production of by heart Radio

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<v Speaker 1>in partnership with house to works dot Com and is

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<v Speaker 1>produced by Tyler Klang and Ramsey Out. For more podcasts

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