Hey everyone.

My name is Chris Anderson, and I'm at Biscayne National Park.

That's right.

I am in a national park right now.

Biscayne is 95% underwater, and it protects the third largest coral reef in the entire world.

This reef thrives in the warm ocean currents off the coast of Florida.

But why is this water so warm?

And why is there a current here anyways?

And how does the ocean move water and heat around the planet?

Let's find out today OutSCider Classroom!

[Water splashing] [Intro music] [Music] This reef is one of over 4000 found in Biscayne National Park.

Coral reefs are among the most bio diverse ecosystems on the planet, rivaling even tropical rainforests.

25% of all ocean species spend some part of their lives in a coral reef, which needs warm, clear waters to thrive.

In Biscayne, the ocean temperatures are a balmy 80 degrees.

But why are these waters so warm?

Let's start with our usual suspect, the sun.

The Earth's surface is continuously bombarded with 173,000 terrawatts of solar energy.

That's 10,000 times the entire electrical output of the planet.

Every second of every day.

So, yeah, it's a lot of energy.

Man, someone should really learn to capture all that.

But ocean water just doesn't sit still.

Currents carry water and heat all around the planet.

Actually, right now we're in a current.

This is the Gulf Stream, which originates in the warm tropical waters of the Caribbean and travels around the southeast United States, all the way up to Europe.

So what drives that motion?

Now I'm about to blow your mind.

Heat doesn't rise.

Heat is energy.

That would be like saying light rises or electricity rises.

That wouldn't make any sense.

But warm things are generally less dense than cooler things, which in a fluid system like our atmosphere, means that warm air masses will rise relative to cooler ones.

Right now we're about 25 degrees north latitude, so we're pretty close to the equator, which means Biscayne gets a lot of direct sunlight.

Air at the surface near the equator is heated, expands, and is forced into the upper atmosphere.

There it cools, becomes more dense, and sinks back down to the surface where it's heated once again.

When a fluid like air is circulating due to temperature and density differences, we call that a convection current.

Convection currents can be found throughout the Earth.

They're in our atmosphere and our oceans, even inside the Earth, in the mantle.

Understanding convection currents is really essential to understanding a lot of systems on our planet, which is why it's so important you stay up on "current" events.

[guitar riff] ["Ooo yeaaah"] The convection currents in our atmosphere make for prevailing surface winds that push water around our oceans.

It's this cycle of air being heated by the sun moving into the upper atmosphere, then sinking as it cools, that drives ocean currents.

But heat isn't the only factor at play here.

To help us understand what else influence ocean currents is my friend and marine scientist Angelique Rosa Marin.

Our planet moves, it rotates on its own axis, and basically how ocean currents are affected by this rotation, it's because this effect calls the Coriolis Effect.

So the Coriolis Effect, it's, it's a force that is caused by the rotation of our planet that creates that our currents and also the winds goes to a specific like direction in the north part of our planet and in the south part.

It's specifically that driving force in the north part, it's gonna influence on the winds, and they're gonna move to the right side clockwise and in the southern part are gonna move to the contrary part.

And how this affect the ocean currents, and so we're saying it affects the direction of the winds, and the winds plays an important, crucial role in the creation and also the development of the ocean currents around our planet.

Specifically, here we are in Florida.

We are in the Biscayne Park, so we are in the northern part of our globe.

So in this case here, basically the currents and as we are seeing here in the park, are going to move to the right.

Ocean currents don't just move water around the planet.

They're also a huge factor in local climates.

Here's a good example.

Most of continental Europe is north of the United States.

Based on latitude alone, you'd expect Spain to have roughly the same climate as Ohio, but that's not the case at all.

And I should know, I live in Ohio.

It gets pretty cold there in the winters where Spain's a lot more temperate.

So, what gives?

The Gulf Stream, the current that runs around Florida and through Biscayne National Park, brings warm water from the Caribbean north all the way to Europe.

Without the Gulf Stream, Europe would experience much cooler temperatures than they do today.

Ocean currents are one of the most important ways heat moves around the planet.

Here's another way oceans impact climate.

Water has what's called a high specific heat, meaning it takes a lot of energy to change its temperature.

If you live by the ocean or lake or even if you have a pool in your backyard, you know that while air temperatures can be pretty hot in June, the water can still be too cold to go swimming, and the opposite holds true.

Sometimes the water is nice enough to go for a dip well into fall.

So how does that impact climate?

Areas near the ocean tend to experience less extreme temperatures because the water stabilizes the climate.

It takes a lot of energy to change its temperature.

But if you're in the middle of the continent, you don't have that stabilizing force on your climate, and temperatures can be a lot more swinging.

Biscayne is a super fun park to visit.

You can paddle through mangroves or go scuba diving or snorkeling on the coral reefs.

Check out the Biscayne National Park Institute.

They've got a bunch of awesome tours and super knowledgeable guides.

Just remember, the ocean can be a dangerous place.

Being an experienced swimmer in this park is a must.

So if you're not comfortable swimming, being out in the open ocean might not be for you.

And if you're ever out in a boat, make sure you know where the fire extinguishers and life jackets are before you set sail.

Hey, even pirates put safety first.

Actually, they probably didn't put safety first, but you should.

Happy exploring.

[Music] Along the coast of Biscayne lies one of the most important and unique forest in the entire world.

They're filled with mangroves, trees that grow in coastal areas in tropical and subtropical areas.

These trees provide a home for birds, mammals, reptiles, and, of course, fish.

But why they so salty?

Sorry.

How are they able to grow in such a saline environment?

Oh, don't ask me.

I don't know how a whole forest of trees can grow in the ocean.

Let's ask someone who does.

Doctor Lola Fatoyinbo is an environmental scientist who studies mangroves around the world.

She can tell us how these trees are able to grow in saltwater and what they do for other species.

Hi, my name is Doctor Lola Fatoyinbo and I'm an environmental scientist who studies mangroves.

So mangroves are trees that grow in coastal zones, in the intertidal zone, in tropical and subtropical regions worldwide.

Mangroves have this really amazing ability, which is that they are able to grow in water and not only in freshwater, but they're actually able to grow in saltwater, so they can grow in coastal areas.

And they're able to do that because they are really adapted to the environment that they're growing in.

They have these amazing prop roots or aerial roots that basically stabilize them in like really wet soil.

One of the species, the black mangrove, is able to essentially excrete the salt right back out of its leaves.

So when you walk by a leaf, sometimes you see some salt on them.

And one of the other species, the red mangrove, is actually able to filter out the water before it goes into the stem.

The most iconic thing when you look at a mangrove is that they have these really, really big roots.

You have some roots that are prop roots.

So roots that look like props, essentially that hold them up.

And then you have some other species that have what we call pneumatophores.

They're like snorkels, essentially tiny little pencils coming out of the sand or out of the water.

Mangroves provide habitat for many, many types of animals, both aquatic and terrestrial.

And you can find mammals as well depending on where you are on the planet.

You have some really, really iconic animals that live in mangrove ecosystems.

Mangroves aren't just good for birds and fish, they're also important for us humans as well.

The roots of the mangroves can really take a beating from the waves, which is important because it protects coastlines from erosion.

These root systems also trap mud and sand as the tide rolls in.

Mangroves basically build their own islands, which, while extremely cool, also protects coastline, buildings and structure.

Mangroves provide a lot of what we call ecosystem services to humans.

They are able to protect the shoreline from erosion.

They protect areas that are behind them from a lot of the strong winds and waves that come from the ocean.

They essentially act as a buffer.

They're also really important as trees that are able to protect us from climate change.

They are able to absorb carbon dioxide from the atmosphere and they store it in their trunks.

But they're also able to store a lot of carbon in the soil because they grow in these aquatic areas.

And so mangroves are what we call really, really important carbon stocks.

So they keep a lot of carbon in the trees and in the soil and keep it from going into the atmosphere.

Thanks mangroves!

Sadly, many of our mangrove forests in the US have been lost due to human development.

It's nice to have a room with the view, but it's even nicer when said room doesn't fall into the ocean because the coastline has eroded away.

Good news is there are groups that are working to restore mangrove habitat.

The Fabien Cousteau Ocean Learning Center has planted more than 35,000 mangroves in Florida alone.

They do a bunch of cool restoration projects.

See how you can support groups like this or how you can restore habitat where you live.

[Music] I'm Doctor Jeanette Davis, also known as Doctor Ocean, and I'm a marine microbiologist, which means I study the things in the ocean that you can't see without a microscope.

And I'm also a bestselling children's science book author.

[Woosh, pops] [Ding] The ocean is really special and great.

In fact, over 70% of our planet is ocean.

And when scientists are looking for life, on other planets, the first thing that they do is they look for water.

Because life as we know it depends on water.

So the ocean is really important.

It provides protein, it provides food.

It's also a source of new medicines.

It provides recreational activity which are good for our mental health.

There are so many great things about the ocean.

And no matter where you live, you should definitely thank the ocean for even the oxygen that you breathe, every other breath that you take comes from the oxygen in the ocean.

There's so much to understand about the ocean.

My specialty is actually finding new drugs from the ocean.

And so when we are sick as human beings, we take medicines in the form of a liquid or a pill.

But those, medicines are actually chemicals.

And the ocean is the largest and the oldest habitat on the planet.

So it has lots of chemistry and lots of chemicals.

And so what I do is I explore the bacteria, the things that you can't see without a microscope in the ocean, looking at the DNA to see if I can discover new bacteria that can produce medicines that we can use when we're sick.

So I was a typical inquisitive kid, very curious.

Love the outdoors, love exploring.

And those are the natural attributes of a scientist.

And so I just kind of stay with it as a kid.

I kept with that kind of inquisitive nature, and I found that science was actually the avenue for me to remain curious.

So I stayed with science.

By the time I was in fifth grade, I knew for sure that I love science.

I had an amazing fifth grade science teacher.

And that really introduced me to the world of science.

And from then, I just knew that's what I wanted to pursue in life.

I, you know, when I went to Hampton University for undergrad and I walked into the marine science building and our first class, one of the things that they ask you is like, why did you become interested in ocean science?

And everyone had these great stories about growing up, going fishing, or going to the beach and all of this stuff.

And I was like, I literally just sat outside on the water of the campus and looked over and saw a marine science and said to myself, I'm going to try it out.

So, I don't necessarily remember any particular moment where it was like, yeah, this, this great thing about the ocean that led me to ocean science.

But I do know once I got into the marine science and saw that the ocean was studying a variety of sciences, which I love science generally.

That's why I knew ocean science was for me.

And in my first internship, I sailed the Chesapeake Bay, lived on a 53ft boat with a crew of 13, which was really difficult yet exciting.

And once I did that and lived out on the ocean, I said, yeah, this is definitely for me.

So I would say that would be my “Aha” moment.

You know, science is a field that, can be difficult, but we need more people involved and engaged in science because it helps solve problems for humanity.

Right.

And so I think when you hear the word science or you think about science, you do think it's one particular path.

And so I would advise them to again follow your curiosity.

Science is broad.

You're needed in the field to help solve problems and pursue your dreams.

There are so many unanswered questions.

There's so much to explore.

So just trust your ability to ask and answer questions, because that is the foundation of science.

[Music] Not every biome is on land.

Some are completely underneath the water, and one of the most beautiful are coral reefs, like the ones found in Biscayne National Park.

Reefs are a rainbow of colors filled with fish, invertebrates, reptiles, birds, mammals and you guessed it, corals.

They're one of the most ecologically productive ecosystems on Earth, and their biodiversity rivals even tropical rainforests.

Get ready to dive into your next biome.

It's coral reefs.

[Biome Tour Song] I'm on a biome tour trekking pole in my hand and peeping each and every climate that's out there, man.

Grasslands, tundra, taiga, wetlands.

I'm on a biome tour trekking pole in my hand.

Checking abiotic factors on the sea and land.

Desert, rainforest, coral reefs, chaparral.

[Music continues] Since they're not on land, coral reefs aren't impacted by climate patterns the way other biomes are.

But that doesn't mean climate doesn't make a difference.

Reefs need warm water and lots of sunlight because of symbiotic photosynthetic algae that live within the coral tissues.

More on that later.

Point is, no sunlight, no photosynthesis, no coral reefs.

That means the best environments for coral reefs are places with warm, shallow, clear waters.

And where can you find those kind of conditions?

Same place you can find hidden bank accounts.

The tropics.

With reefs living in tropical oceans.

They're exposed to a lot of sunlight year round, making them extremely ecologically productive.

Who captures all the sunlight?

Phytoplankton.

Coming from the Greek word phyto, meaning plant, and plankton meaning.

plankton, these microscopic floaties drift about the water, photosynthesizing at their leisure.

Filter feeders do pretty much what you'd expect.

Filter the water for things to eat, usually microscopic organisms like the aforementioned plankton.

Sea anemones, sea squirts and sponges are all filter feeders and either have tentacles or feathery appendices that direct water into their mucous lined mouths.

But the big players are the coral polyps that build the reefs.

They construct their homes by taking dissolved carbon dioxide and calcium from the water and turning it into calcium carbonate, otherwise known as limestone.

They then throw out their tentacles and catch anything that goes by.

They also have a symbiotic partnership with algae, providing them a home in exchange for extra food.

There's dozens of species of coral that live in Biscayne.

DOZENS!

You got ya brain coral, ya lettuce coral, ya fire coral, ya elkhorn coral, ya staghorn coral.

Lots of corals!

All with their own tiny little limestone apartments.

Yep.

The organisms that build these giant reefs are just tiny little polyps that eat whatever the current brings to them.

The corals, of course, are a food source themselves, but they also provide a home for countless species.

There's invertebrates like moon jellies, brittle stars, reef octopi, spiny lobsters, reptiles like green sea turtles, and mammals like manatees and bottle nose dolphins.

[record scratch] Speaking of, there's dolphins right there!

Oh my God, oh my God.

Bottlenose dolphins!

Oh my God.

[Chris gasps] Did you get it?

Yeah.

Here's a list of all the fish species that have been found in Biscayne National Park.

[Subtle jazz music] Man!

That sure is a lot of fish species.

Abundant sunlight, food and habitat makes coral reefs prime real estate for marine species.

While they only cover 0.1% of the world's oceans area, reefs are home to 25% of all ocean species.

And it's microscopic phytoplankton and coral polyps that thrive in the warm, clear, shallow waters of the tropics that support all that life.

Together, they form the foundation of one of the most important biomes on the planet.

[Music] Coral reefs are super important ecosystems.

They provide food and habitat for so many unique species, and they've been around for a really long time.

Did you know that the first coral reefs evolved 485 million years ago?

In fact, some modern reef ecosystems have been functioning continuously for over 10,000 years since the end of the last ice age.

Sadly, human activity is putting the world's reefs at risk.

How?

Humans have been dumping a little gas into our atmosphere called carbon dioxide.

Perhaps you've heard of it since the dawn of the industrial era, when fossil fuels like coal and gasoline have been burned for energy, carbon dioxide levels in our atmosphere have gone from 280 to 420 parts per million.

[old timey piano] What's the big deal?

It's just a little extra gas.

I got a little after gas all the time.

These molecules, while small and making up only a tiny fraction of the gases in our atmosphere, are really good at holding on to heat, which is why our planet is getting warmer.

To teach us why this is all so bad for coral reefs is my friend and marine microbiologist Doctor Jeanette Davis.

I'm Doctor Jeanette Davis, also known as Doctor Ocean.

And I'm a marine microbiologist, which means that I study the things in the ocean that you can't see without a microscope.

And I'm also a bestselling children's science book author.

Ocean acidification is a phenomenon that's currently taking place due to climate change.

And just to take a step back, our planet has a natural heating and cooling system.

And as we produce more CO2 or carbon dioxide in the environment, it is a part of, like the heating system of the planet.

So CO2, methane and various gases, it's almost like covering the Earth with a blanket.

And the more CO2 that we put in the atmosphere, the more those blankets cover the earth, which makes it warmer.

So a warmer planet means a warmer ocean.

And so the ocean works with the atmosphere and the CO2 is absorbed, from the atmosphere into the ocean.

And so now we have more carbon dioxide, not just in the atmosphere, but also in the ocean.

And as the ocean is taking up some of that CO2 or carbon dioxide, it produces something called hydrogen ions.

And these hydrogen ions make the ocean more acidic.

So overall, more CO2 makes more hydrogen ions, which means more acid in the ocean, which leads to ocean acidification, which is a really, important thing to study because it's not great for the environment, overall.

Some of the negative impacts of more ocean acidification, in the ocean environment is that it negatively impacts organisms that form skeleton or shells in the ocean environment, and that includes corals or oysters and clams and things like that.

So these organisms naturally need something called limestone or what we call calcium carbonate.

And again, because there is excess in hydrogen ions, they bond with this carbonate, to form another chemical bond.

And so organisms such as corals no longer have the carbonate that they need to form their skeleton.

So essentially, acidic environment or ocean acidification, doesn't allow corals or other shell forming organisms to have the needed environment to build their skeleton and maintain a healthy ecosystem overall in the environment.

Coral reef environments are actually known as the rainforest of the sea because so many other organisms depend on coral reef environments.

So plants, sea turtles, fish, birds.

They use coral reef environments for shelter to find food, to reproduce, to even rear some of their, their, their young in the nooks and crannies of a coral reef environment.

So if they are not healthy, it also means that thousands of other organisms are also not healthy and safe to have the environment that they need to thrive.

A warming and more acidic ocean spells trouble for the world's coral reefs, but there is work being done to protect them.

Researchers are trying to understand which coral species are the most resilient to climate change, and there's been some projects that have shown some really promising results in seeding reefs with these more climate resilient species.

One such project is called Coral Vita.

They have a special process that allows corals to grow up to 50 times faster than they normally would in the wild.

They then train the corals to live in more acidic and warmer ocean conditions.

It can be a real game changer for dead and dying reefs.

The Biscayne National Park Institute also does a lot of really important research on reefs here in the park.

Now, I know what you're thinking.

"A warming, more acidic ocean is horrible.

How can I help?

But also, I don't live super close to an ocean or know anything about growing coral.

But the closest thing I have to an ocean is a Red Lobster."

Here's the thing.

We need to cut our fossil fuel usage.

That's the bottom line.

And while change needs to happen at the biggest of scales, individuals and yes, that includes kids, can collectively make a difference.

So ride your bike or take the bus where you're going, If you can.

Make sure you recycle, buy local food.

Don't water your lawn so much.

Buy your clothes second hand.

And whatever you do, support local, state, and federal leaders who will take meaningful action on climate change.

Well, that's our show.

Thanks for watching.

Now, if you'll excuse me, I have some thermohaline flow rates to measure.

We'll see you next time on OutSCider Classroom!

[Music] Major funding is provided by the National Geographic Foundation.

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