Hey Squeaks, I've got a question for you.
How often do you think about the ocean?
Yeah, all the time.
Me too.
There's just so many amazing things in the ocean.
Really big creatures, really big waves, and really cool sharks.
Oh, what's the biggest thing in the ocean?
Well, I can tell you what the biggest animal is.
It's a kind of whale, the blue whale.
And Jesse can tell us all about them.
Hey there!
Squeaks was just showing off his imaginary sea monster that he drew based on some sea monsters of the past.
I think it's great!
I see that it has sharp teeth, big flippers and an armored head, like the animals we learned about before.
And I see you drew yourself swimming next to your monster.
Your sea monster is huge!
But even your imaginary sea monster doesn't look as big as the biggest, biggest animal that's ever actually lived.
Do you know what animal that is, Squeaks?
It's a kind of whale called the blue whale, and they're still around today!
Blue whales can get to be over 30 meters long, about as long as three school buses in a row.
And a blue whale's tongue can weigh as much as an elephant.
And just its heart can be as heavy as a car.
So what do you think these great, big blue whales eat?
Fish!
That's a great guess.
And some whales, like beluga whales, do eat fish.
They have sharp teeth that they use to catch and eat their prey.
But some whales, like blue whales, don't have teeth at all.
Weird, right?
These whales have something called baleen instead of teeth.
Baleen is a bristly plate that's stuck to the roof of the whale's mouth.
It looks like a big, bristly broom inside their mouths.
That's a great question!
How does it help them eat?
Well, if you've ever seen someone cook pasta, they might have dumped it out of the pot and into a strainer when the pasta was done cooking.
Water pours out of the strainer, but the food stays inside.
Baleen works kind of the same way.
When a whale that has baleen takes a gulp of water and food, they use their tongues to push all the water out through the gaps, but keep the tasty food inside.
But if they aren't eating fish, What are they eating?
Blue whales eat tiny animals called krill.
Krill are so small that we need a microscope to see them clearly.
That's right, Squeaks!
Something as big as a blue whale does need to eat a lot of krill.
And they do!
Adult blue whales can eat 16 tons of krill each day.
That's as heavy as four elephants!
Isn't it amazing that such a huge animal eats things that are so small that we can't even see them?
Baby whales are called calves, just like baby cows.
And also, like cows, whale calves drink the milk that their mothers make inside their bodies until they're old enough to start eating krill.
That's because all whales, including blue whales, are mammals.
Mammals are animals like horses cows, dogs and humans, and all mammals feed their newborn babies milk.
That's one of the special things that makes an animal a mammal.
Yeah, they do look more like a fish than like the other mammals.
But fish don't feed their babies with milk, which helps us know that whales and fish are different.
And there's another important feature that tells us that whales are mammals and definitely not fish.
Whales don't have gills to breathe in water like fish do.
They have lungs just like us.
So, even though some whales can hold their breath for over an hour, they have to come up to the surface of the ocean to breathe every now and then.
When we breathe, air goes through our nose or mouth and into our lungs.
Whales breathe using their lungs, too, but they do it in a very special way.
They breathe in and out through a hole on the top of their head called a blowhole.
When a whale is ready to take a breath, it comes up to the top of the water, opens its blowhole and breathes out.
This is called spouting.
That air shoots up into the sky, sometimes about 12 meters high.
That's about as tall as six grown-ups if they stood on each other's shoulders.
The whale breathes fresh air in through its blowhole and goes back underwater.
When a whale is underwater, they can pinch their blowhole closed from the inside and seal it shut so no water gets in.
But my favorite thing about blue whales are the amazing sounds they make.
Blue whales, as well as lots of other whale species, can talk to each other from really far away.
Sound travels really well in water, so one whale can hear another whale making noises, even if they're thousands of miles apart.
Whales make lots of sounds, including squeaks, whistles and long low booming sounds that scientists call songs.
Here's what a blue whale's song sounds like.
I think whale songs sound beautiful, too, Squeaks!
Oh yeah, Squeak says he still thinks his imaginary sea monster is pretty cool.
But it's even cooler that there are giant blue whales out in the ocean right now singing to each other, eating microscopic krill and taking care of their babies.
I agree, blue whales are so incredible.
I especially love the idea that they can sing, and they're not the only amazing animal in the ocean.
I mean, how about sharks?
Sharks are amazing hunters, maybe the greatest in the whole ocean.
From their super cool skeletons to some very old sharks, let's learn a little bit more about them.
When you think of a shark, what do you picture in your mind?
Do you think of a big fin sticking out of the water?
Or maybe a huge set of sharp teeth?
Sharks are some of the most famous animals in the ocean.
But do you know what makes a shark a shark?
Well, for one thing, all sharks are famous.
That might not surprise you, since they live and swim in the water, but sharks are a special kind of fish.
One of the things that makes them different from other fish, like goldfish, is that sharks have a special skeleton.
Our skeletons are made of bone, and so are the skeletons of most kinds of fish.
But a shark's skeleton isn't made of bone.
It's made of cartilage.
And you have cartilage in your body, too.
You can feel it right now.
Touch the tip of your nose.
Wiggle it around.
How does it feel?
What about your ear?
Can you bend it?
You sure can, because the tip of your nose and your ear aren't filled with bone.
They're filled with cartilage.
Cartilage is a lot lighter than bone, and it bends easily.
So having a skeleton made of this stuff helps sharks swim farther and faster than if their skeletons were made of bone.
Now let's look at another body part that sharks are famous for — their teeth.
Have you ever lost a baby tooth and then an adult tooth grew in?
Sharks lose their teeth all the time, throughout their entire lives, and they just keep growing new ones.
How can they do that?
You and I just have one row of teeth in our mouths, but sharks have lots of rows of teeth on the top and the bottom.
So when a shark loses a tooth, another tooth that's right behind it can just move on up to take its place.
Because they always have new teeth to replace the old ones.
Some sharks can lose thousands of teeth during their lives.
Alright, the next cool thing about sharks? their skin.
If you could rub the skin of a shark, you'd find that it would feel smooth if you ran your hand in one direction.
But if you rubbed your hand the other way, it would feel rough, like a cat's tongue.
That's because a shark's skin is covered in tough bony scales that actually look a little like tiny teeth.
These little scales are stacked on top of each other like tiles on a roof.
This helps sharks swim through the water quickly and quietly.
So those are some of the things that all sharks have.
But there are over.
There are 450 types of sharks in the world, and that means a lot of differences too.
Take a look at this one.
It's called a whale shark, and it's the biggest shark there is.
In fact, it's the largest fish in the whole world.
Whale sharks can grow to be as long as a school bus, but even though they're so big, they plants and super small animals called plankton that float in the water.
But not all sharks are as big as the whale shark.
Some can also be tiny.
Meet the dwarf lantern shark.
It's so small that it could fit in my hand!
This shark lives in the deep ocean where there's very little light, so it has big eyes to help see in the dark.
Plus, it has a really neat feature.
It has special organs on its belly, fins, and tail that actually glow.
Scientists think this might help the lantern shark lure in prey for it to eat.
Plus, when it's in shallower water, where there's more light, these glowing lights can help it blend in to avoid predators.
Finally, I'd like you to meet a very special shark.
Say hello to the Greenland shark!
This big shark spends most of its time swimming in very cold water, hanging out near the sea floor looking for an easy snack.
But scientists have recently discovered something amazing about these animals.
Greenland sharks can live to be up to 400 years old!
Of all the animals in the world with backbones, known as vertebrates, Greenland sharks live the longest, at least that we know of.
But scientists are still discovering new kinds of sharks all the time.
So who knows what kinds of super sharks are still out there waiting to be found?
Oh, Squeak says he wants to discover new kinds of super sharks.
Maybe you will.
But even though we've talked about some amazing ocean animals, the ocean themselves are incredible too.
Let's see, how about the biggest waves?
Oh, waves can get really big, big enough that people in some parts of the world have to learn how to be safe around them.
Let's take a look at tsunamis.
One of my favorite parts about going to the beach is watching the ocean.
When Squeaks and I visit, we like to sit for a while just watching the waves splash against the rocks and sand.
And sometimes, when it's hard for Squeaks to fall asleep, he'll listen to sounds of the ocean, waves to help him relax and get sleepy.
Most waves are like that, small and calm.
But once in a while, there's a really extreme kind of wave.
It's called a tsunami, or sometimes a tidal wave or seismic wave, and it's huge.
The wave can be taller than a house.
Tsunamis usually only happen in the part of the world near the Pacific Ocean, and there are only one or two a year.
But they make a big splash.
Regular ocean waves aren't usually very big, and they follow a pattern.
The water moves back a little bit and then rises up into a kind of half-circle shape and splashes onto the shore.
During a tsunami, the water does something similar, but it moves much more.
The water pulls far away from the beach, going back and back, until the water comes zooming back in all at once as a giant wave.
Yeah, it's really strange to imagine.
Tsunamis don't happen a lot, because a lot of different things need to come together to cause one.
It all starts way out in the ocean, with a big movement on the ocean floor.
Good question!
Squeaks wants to know what could make the ocean floor move around like that.
Well, earthquakes do that sometimes, and it can also happen when underwater volcanoes erupt.
Yes!
There are volcanoes underwater!
And when something like an earthquake or volcano makes the ocean floor shift quickly, it pushes water out of the way super fast.
That's called displacement.
The water gets moved to a different place.
It's what creates the waves.
It's just like when you drop an ice cube into a glass of water, or even when you get into the bathtub.
You displace the water, and the moving water creates waves.
But when the ocean floor moves around, that creates much bigger waves than just dropping an ice cube into a cup of water.
And the waves get bigger and bigger as they get closer to shore.
A tsunami wave can grow almost 30 meters tall, way taller than most buildings.
When a wave that big hits the shore, it can be very powerful, and smaller waves can follow behind the first one, bringing in a lot of extra water.
The water can flood whole towns, covering houses, schools, and everything else for a while.
Eventually the water pulls back into the ocean and sometimes it'll take things with it like trees or cars.
That's some strong water!
Tsunamis can be dangerous Squeaks, but we have lots of ways to know when a tsunami might happen and to stay safe when they do.
Some scientists have earthquake sensors that can tell them when there might be enough displacement to cause a tsunami.
When they know a tsunami could happen, they send messages to the people that live by the beach so everyone in town can go somewhere safe.
And if there are people on the beach, they'll see the ocean start to pull very far away, getting ready for that big wave.
So that's a clue to get to safety.
Where do people go?
Well, to stay safe during a tsunami, the best thing to do is to move somewhere high above the ocean so that the tsunami and the flooding afterwards won't be able to reach you.
But thankfully tsunamis don't happen a lot and there are lots of scientists keeping an eye out, just in case.
That way, we get to safely enjoy the ocean.
Oh, you think giant waves sound scary?
Well, they are.
But luckily, scientists help us stay safe when they happen.
There are lots of things about the ocean that are scary, but really cool too.
Like, can you imagine swimming in the coldest ocean in the world?
These animals do, and they're perfectly happy to risk a bit of a chill.
Hi, there Squeaks and I have been learning all about Antarctica, a place so cold it feels like winter all year round.
Oh, Squeak says his favorite thing is the penguins!
We learned all about them too, like how they look funny on land but are super graceful in the water.
Oh yeah, you're right that you won't see many other animals on land in Antarctica.
But looking below the surface of the Southern Ocean and the Antarctic seas, you'll find a very different story.
Even though it's freezing cold, penguins and many other animals swim in the seas surrounding Antarctica.
These are called marine animals.
Marine is a word that tells us these animals live in the ocean.
I would have a really hard time swimming there, too.
It's so cold!
But for these marine animals, the super-cold ocean is a great habitat.
A habitat is a place that provides everything an animal needs to live, like food and a place to stay.
These animals are part of a huge food web in the ocean, with different animals that live and swim near each other and even eat each other.
And each creature in this food web has a special way to survive the cold.
How is that possible?
Well, let's take a look at this leopard seal.
Do you see anything that would help them keep warm?
Good observation, Squeaks!
It can be hard to tell sometimes because the seal is wet, but they have a warm fur coat.
But that fur on its own wouldn't be enough to keep them warm.
So seals actually have another secret layer that helps them stay warm while they're swimming in cold water.
How do they do it?
Under their skin, seals have a special layer of fat called blubber.
This blubber doesn't get cold easily and acts like a super thick coat between the cold seawater and the warmth inside the seal's body.
Most marine creatures like seals, whales and orcas and penguins have some amount of blubber, especially around Antarctica.
And being big and blubbery helps to keep the cold outside of their bodies instead of having it sink in and freeze their insides.
Good question!
Not every animal has blubber, so how else could swimming creatures stay warm?
Well, not every animal needs to stay really warm to survive.
Squeaks, what's another animal that you might think of when exploring underwater habitats?
You're right!
They are so neat!
Different species or types of fish can live in marine habitats all around the world, including in freezing cold Antarctic waters.
Fish are part of this food web, too.
They're food for penguins, seals and orcas, so it's super important that there are fish that can survive in the cold.
Take a look at the group of fish called notothenioids.
These fish don't have blubber, so the insides of their bodies get cold enough that it could freeze another animal.
No worries, buddy!
Notothenioids have a special adaptation that stops them from freezing.
Their blood has special substances that lower the temperature at which liquid water freezes into a solid.
We call substances like that antifreeze.
Even though notothenioids live where it's cold enough to freeze water or a person, the antifreeze in their blood keeps the fish swimming along without becoming fish-sickles.
It would be really interesting to have antifreezing blood!
For many animals like notothenioids, their chilly home is just fine by them.
There are sometimes other problems because of the cold, though.
Well, let's go from looking at big animals to teeny tiny animals.
A favorite food of many Antarctic sea animals are teeny little critters called krill.
Krill are related to crabs, lobsters, and shrimp.
Antarctic krill's insides don't need to stay as warm as a bird's or a mammal's, so they don't have fur feathers or even blubber to keep themselves warm.
They can even grow faster in colder waters.
Krill eat phytoplankton, which are itty-bitty things similar to plants that grow in the water.
Some phytoplankton grow well in the cold.
But when winter comes to Antarctica, the seas get too cold and there aren't as many phytoplankton for krill to eat.
Well, the krill survive without food by shrinking.
Adult Antarctic krill can molt or shed parts of their bodies.
They can even use some of their old body parts kind of like food, so they can shrink down and stay alive.
When the summer comes and the waters become slightly less cold, the phytoplankton come back and the krill grow big again.
It does sound like it might be hard to grow and shrink so often.
But without these super-survivor krill, so many animals would go hungry.
Krill are eaten by fish, penguins, seals, whales, and even more marine mammals.
Each of these animals in this freezing food web has their own unique adaptations to help them deal with problems that come from living in extreme cold.
Whether we're looking at the blubber of seals, the amazing antifreeze blood of fish or the shrinking skills of krill, each animal survives in its own way.
And many of these animals rely on each other.
The bigger animals need there to be plenty of smaller animals there to survive.
Without the tiny krill, there wouldn't be big whales.
Yeah, isn't it neat how everything's connected?
Even in one of the coldest places on Earth, there's so much to learn about animals and how they live, eat and survive.
Say why don't we find some videos about krill and learn about eating in the cold while we eat something cold?
I have some ice cream in the freezer for us!
Yeah, I don't think I could swim in water that cold either, but I do love a day at the beach.
Hey Squeaks, we've been talking about the biggest and most extreme things in the ocean, but there's one thing I can think of that's just the best, and that's having fun.
Like, do you remember when you and Jesse learned how to make the best sandcastle ever?
I sure do.
It's time to head outside and play!
And it's summer, so you know what that means!
We can play in the sand!
Maybe you've had a chance to play in some sand too, in your own yard or at school, or even at the beach.
If you have, you know it can be a lot of fun to play in.
Sometimes I let sand flow through my fingers or have squeaks bury my hands or feet.
But one of the coolest things that you can do with sand is build stuff.
Yes, Squeaks like sandcastles!
But it can be tricky to build a sandcastle that doesn't just crumble away.
Big sandpiles are fun, too, but they're no castle.
So here are four tips to help you build an awesome sandcastle.
Step 1.
Use plenty of water.
Water is the key to building a great sandcastle, because sand that's too dry doesn't stick together at all.
And here's why.
If you could look at sand closely — I mean really closely — you would see that it's made of tiny pieces called grains.
If you try to build a sandcastle out of dry sand, the grains just fall apart.
There's nothing to hold them together.
But if you mix water in with the sand, then something really neat happens.
Little drops of water so small that you can't see them squeeze in between the grains of sand.
The teeny water droplets stick to the grains of sand and form what are kind of like little bridges between the grains.
These bits of water act like glue to hold the grains of sand together.
If you don't use enough water, there won't be enough of these bridges, and the sand will fall apart.
So make sure you mix plenty of water in with the sand that you're going to use to build your sandcastle.
Step 2.
Give your sand away and some time to drain.
Draining the sand means making sure there's not too much water in it.
If it starts to look more like soup, that means there's too much water for those little bridges to form and the grains of sand won't stick together.
So you should let the extra water drain from the sand before you start your castle.
That might mean using a tool with holes in it, so the extra water can get out.
Or you might just want to let your sand sit for a few minutes before you get started.
Once the extra water is drained out of the sand, you're ready to move on to step number three.
Make the castle's base.
Every sturdy building, whether it's a skyscraper or a sandcastle, needs a sturdy base, or bottom.
If the bottom isn't strong enough to hold it up, it could crumble or tip over.
A good sandcastle base is made out of tightly packed sand.
So if you're using a bucket or a cup, Make sure you press on the sand to pack it in tightly.
And if you don't have a bucket or a cup, no problem!
Just make a pile of sand, and press on it as hard as you can.
Then add more sand on top, and press again.
Do this over and over again, until you have a nice big pile of sand that's tightly packed.
Step 4 — Use your imagination to make your castle awesome!
Once you have a nice, sturdy base, you're ready to shape your castle.
You can use your hands and fingers to shape the walls.
Then, you're ready to add towers, seashells, or anything you can imagine!
Just make sure not to add too much sand on top of your base, or your castle might crumble.
And no matter what kind of castle you build, don't forget to have fun while you're doing it!
All right, I think Squeaks and I are going to go play in the sandbox now.
I have a few ideas for how to build an amazing sand fort.
If you all want to keep learning with me Squeaks, Jesse and all of our friends be sure to subscribe and we'll see you next time here at the fort.
