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It`s Okay To Be Smart, The Mystery Behind Earth’s Most Epic Migration - YouTube

The Mystery Behind Earth's Most Epic Migration - YouTube

- When you think of Earth's largest animal migrations,

you might picture massive herds making their annual trek

across the Serengeti or transcontinental flights

painting the sky orange each year.

But Earth's biggest mass migration

actually happens every single night and it's underwater.

During World War II, submarine Sonar recorded these strange

dense signals rising from the deep

as if parts of the ocean floor were moving up and down

by as much as 3,000 feet.

The sea floor wasn't moving.

The sonar was actually detecting huge masses of tiny animals

known as zooplankton

ascending from the depths to the surface every night

and returning down again.

Turns out this happens in every ocean, every night

and scientists were completely bewildered.

I mean, why do these nearly microscopic plankton

make such an incredible daily journey?

Turns out the answer could be linked to phenomena

as seemingly unrelated as biological clocks

and even climate change.

Hey, smart people, Joe here.

This is the strange story

of Earth's largest and most mysterious migration.

(bright upbeat music)

- Vertical migration in the ocean is the largest

net animal movement on our planet.

It's really remarkable.

I'm Kelly Benoit-Bird, a senior scientist at MBARI,

the Monterey Bay Aquarium Research Institute

where I use sound to study lives of ocean animals.

- So first, you really need to appreciate

how tiny zooplankton are.

Like smaller-than-the-tip-of-a-crayon tiny

but the distances they move in the ocean

are absolutely immense, for them anyway.

- If we were to scale the migrations to a human,

we'd be talking about you doing a 10K twice a day,

once to get your breakfast and once to go to bed

but you'd have to swim at twice the speed

of an Olympic marathon runner.

It's a pretty remarkable endeavor each and every day.

- If you add up all of the vertical migration

happening in all the oceans and lakes on earth,

scientists estimate 10 billion tons of biomass,

25 times the mass of all humans on earth

is racing between the surface and the deep every night.

It's called the diel vertical migration or DVM for short.

But why go to all that trouble?

- Vertical migration is probably

one of the most common behaviors that we see in the ocean.

It happens from the smallest animals to some of the largest

and the most abundant, in terms of biomass,

migrators are typically small fish

like bristlemouths and lantern fish

that are following the vertical migrations

of the zooplankton.

It is a pretty different way of thinking,

most often we've thought about plankton,

all of the plankton as just wanderers

like the Greek word for plankton defines them

but they are are capable of making decisions.

- Zooplankton live in the twilight zone.

No, not that twilight zone,

though some do look pretty strange.

We're talking about the mesopelagic zone,

it's a region of semi-deep water

that receives only about 20% of the light

that you get up on the surface.

- Well, we know that this vertical movement is a real dance,

a balance by these animals to try to get food

which is most abundant in the surface waters

where photosynthesis lets things grow

but while they're trying to avoid becoming dinner

for something else

And so if you're trying to avoid getting eaten,

you wanna be in the dark.

So most often what we see is that animals stay

deep in the dark during the day and then as the sun sets,

they migrate up to the surface

before leaving again at sunrise.

- Responding to tiny changes in light that would prompt them

to move up the water column when the sun went down

and then back down at sunrise.

- But sometimes we see, organisms actually do the opposite.

We sometimes call reverse diel vertical migrations.

- Researchers found that zooplankton move up and down

in the water by as much as 200 feet

just from clouds passing overhead.

That means they're pretty dang photosensitive.

But scientists thought there might be more to the picture.

- Just like those early observers

of diel vertical migration, we're using sound.

Light doesn't penetrate very far in the ocean

so when we try to go down with a camera

with a lot of lights, we're lucky if we see

a few arm lengths in front of us

but sound travels both further and faster in water

than it does in air and so we can get a really large scale

picture very quickly of what's happening with animals.

So we combined those sonar observations

where we send out a short pulse of sound and interpret

how it echos off the animals in the habitat

with low tech tools like nets but also with new techniques,

looking for evidence of the DNA

that these animals leave behind

in the water column, for example.

We kinda combine all these different lenses

to get a complete picture of what's happening

far away from what we can ever see

when we're sitting on a ship at the surface.

- Thanks to all this high-tech study,

scientists have figured out that DVM

is fueled by more than just sunlight changes.

For instance, scientists studying zooplankton in the Arctic

saw that during the long, dark winter months,

zooplankton responded to moonlight instead.

So all of this new information has totally changed

the way scientists think about...

Well, it's changing what we know about plankton altogether.

Okay, so there's a different class of plankton

called phytoplankton.

They're the ones that do photosynthesis

and actually give us most of the oxygen we breathe.

- There are some phytoplankton, some photosynthetic plankton

that also undergo vertical movements.

These are tiny, microscopic, plant-like organisms

that are drifting constantly with the currents

but they can control their vertical movement.

They can control buoyancy

and some of them actually have swimming organs

but typically we see that they're really close

to the surface harvesting sunlight

to photosynthesize during the day and then moving deep

in the water column at night in order to take advantage

of higher nutrient levels at deeper depths.

And so they're sort of shifting the balance

instead of worrying about food and predators,

they're worried about light

and nutrients that they need to grow.

- But that's not all.

It turns out that studying DVM could help us unravel

our own circadian rhythm,

the biological clocks that help our bodies keep time.

The term circadian comes from the Latin phrase circa diem,

which translates to around a day.

And that's pretty appropriate, since circadian rhythms

control many of our day-to-day behaviors.

And most organisms that live on the earth's surface,

including humans, have a system of hormones

and parts of our brain, an internal biological clock

that helps control everything from sleep

to hunger to fertility.

If you're a living thing that lives on land, light

or the lack of light triggers the release of chemicals

that signal that it's time to do certain things.

Like, if you're a bee, these chemicals might send you out

to hunt pollen.

For plants, it might mean moving their flowers

in a different direction.

And for humans, when it gets dark,

our bodies start producing melatonin,

a hormone that helps us relax so we can sleep.

And when it's light, we produce less melatonin

which encourages us to stay awake.

So we know a lot about how these rhythms work

in land organisms

but when it comes to things that live in water,

circadian rhythms were kind of a mystery.

Like, do plankton even have them?

Or are they just little robots that follow light

like a moth to your porchlight?

Well, in 2017,

researchers were studying zooplankton in the lab,

they noticed that not only do they move up and down

during a normal day-night light cycle,

they also found that they migrated

even when the lights were off all the time.

This means these specks of almost alien-like ocean life

might have a circadian rhythm just like we do.

But by far one of the strangest things we're learning

from studying vertical migration is that it might hold

one key to tackling humanity's biggest collective challenge;

climate change.

- Vertical migration plays a big role

in the biological carbon pump.

Organisms that photosynthesize at the surface

take carbon dioxide out of the atmosphere.

If that just stays on the surface water,

it just gets re-released back into the atmosphere.

But if it gets into the deep sea,

it can stay there for thousands of years.

And so by taking that carbon out of the atmosphere

and bringing it to the deep sea,

it is removed from the effects

of that carbon dioxide is having on climate change.

The ocean has done that.

It takes up every year, about 25% of the CO2 that we release

is absorbed by the ocean and sequestered.

Vertical migration is a really fast way to do that.

Animals come up to the surface, they eat those phytoplankton

that have taken up that carbon dioxide

and then they swim down to the deep sea

where they release their waste products,

where they are eaten, where they die.

- If we disrupt vertical aquatic migrations,

we could speed up the collapse of entire ocean food webs

and impact everything from our food supply to the climate.

And all that makes studying the diel vertical migration

even more critical.

- I think vertical migration

is a really important engine for the ocean.

In fact, if there's a fish on your dinner plate,

it probably ate something that was vertically migrating.

So not only is it helping the health of the planet

but it's providing a really key transfer mechanism

for food for humans as well.

I think it's just amazing to think about the world

in as many dimensions as the organisms in the ocean have to.

We're so used to being able to use our GPS

and know that if we come back to the same place,

it's going to look the same while in the ocean,

place isn't really a thing, right?

You stay with the water parcel and that gets swept around.

And if you try to stay in one place,

the characteristics of that environment

would change dramatically through time.

It's really hard to get your mind around

in order to start to think like these animals,

to understand the world that they live in.

- It seems kind of obvious when you say it out loud

but messing with the largest migration on Earth,

this colossal thing that happens every single night,

we could really screw up the planet.

We might even end up krilling ourselves.

(audience booing)

I'm sorry.

Stay curious.

Actually, I'm not sorry, you're welcome.

Hey guys, this episode

was part of PBS's celebration of Earth Month.

You thought Earth Day was good?

We got a whole month and I'd love to tell you

about a new series coming to PBS Terra

called "Untold Earth".

The show is a collaboration with Atlas Obscura

and PBS Nature and it unpacks the mysteries

behind North America's strangest

most unique natural wonders.

There's a link down the description to the first episode

all about redwoods.

We hope you check it out

along with the rest of PBS's Earth Month offerings.

Thank you for watching and like always a huge thank you

to everyone who supports the show on Patreon.

We could not make these episodes without you.

If you'd like to support the show,

there's a link down in description

where you can find out more,

help support the channel

and find out about episodes before anybody else.

Plus you get a notification when we upload videos

so that you can be one of the first people to watch them

which helps other people discover the videos,

which helps other people discover the videos.

It's great.

Check it out, it's down there.

Bye.

- [Speaker] Can you get that through Instagram, huh?

Warm up the pipes.

Learn languages from TV shows, movies, news, articles and more! Try LingQ for FREE

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- When you think of Earth's largest animal migrations,

you might picture massive herds making their annual trek ||||||||подорож

across the Serengeti or transcontinental flights |||||перельоти

painting the sky orange each year.

But Earth's biggest mass migration

actually happens every single night and it's underwater.

During World War II, submarine Sonar recorded these strange ||||підводний чов||||

dense signals rising from the deep

as if parts of the ocean floor were moving up and down

by as much as 3,000 feet.

The sea floor wasn't moving.

The sonar was actually detecting huge masses of tiny animals

known as zooplankton ||зоопланктон

ascending from the depths to the surface every night

and returning down again.

Turns out this happens in every ocean, every night

and scientists were completely bewildered. ||||сбитые с толку ||||збентежені

I mean, why do these nearly microscopic plankton

make such an incredible daily journey?

Turns out the answer could be linked to phenomena

as seemingly unrelated as biological clocks

and even climate change.

Hey, smart people, Joe here.

This is the strange story

of Earth's largest and most mysterious migration.

(bright upbeat music)

- Vertical migration in the ocean is the largest

net animal movement on our planet.

It's really remarkable.

I'm Kelly Benoit-Bird, a senior scientist at MBARI, ||Бенуа||||||МБАРИ ||Бенуа||||||МБАРІ

the Monterey Bay Aquarium Research Institute |Монтерей||||

where I use sound to study lives of ocean animals.

- So first, you really need to appreciate

how tiny zooplankton are.

Like smaller-than-the-tip-of-a-crayon tiny |||||||крейда|

but the distances they move in the ocean

are absolutely immense, for them anyway.

- If we were to scale the migrations to a human,

we'd be talking about you doing a 10K twice a day,

once to get your breakfast and once to go to bed

but you'd have to swim at twice the speed

of an Olympic marathon runner.

It's a pretty remarkable endeavor each and every day. ||||зусилля||||

- If you add up all of the vertical migration

happening in all the oceans and lakes on earth,

scientists estimate 10 billion tons of biomass, |||||біомаси

25 times the mass of all humans on earth

is racing between the surface and the deep every night.

It's called the diel vertical migration or DVM for short. |||суточный|||||| |||дневно-ніч||||дневно-вер||

But why go to all that trouble?

- Vertical migration is probably

one of the most common behaviors that we see in the ocean.

It happens from the smallest animals to some of the largest

and the most abundant, in terms of biomass,

migrators are typically small fish миграторы|||| мігранти||||

like bristlemouths and lantern fish |щетиночерви||| |щетиножаб||світильники| zoals bristlemouths en lantaarnvissen

that are following the vertical migrations

of the zooplankton.

It is a pretty different way of thinking,

most often we've thought about plankton,

all of the plankton as just wanderers

like the Greek word for plankton defines them ||||||определяет|

but they are are capable of making decisions.

- Zooplankton live in the twilight zone.

No, not that twilight zone,

though some do look pretty strange.

We're talking about the mesopelagic zone, ||||мезопелагическая зона| ||||мезопелаг|

it's a region of semi-deep water ||||півглибок||

that receives only about 20% of the light

that you get up on the surface.

- Well, we know that this vertical movement is a real dance,

a balance by these animals to try to get food

which is most abundant in the surface waters

where photosynthesis lets things grow

but while they're trying to avoid becoming dinner

for something else

And so if you're trying to avoid getting eaten,

you wanna be in the dark.

So most often what we see is that animals stay

deep in the dark during the day and then as the sun sets,

they migrate up to the surface

before leaving again at sunrise.

- Responding to tiny changes in light that would prompt them

to move up the water column when the sun went down

and then back down at sunrise.

- But sometimes we see, organisms actually do the opposite.

We sometimes call reverse diel vertical migrations.

- Researchers found that zooplankton move up and down

in the water by as much as 200 feet

just from clouds passing overhead.

That means they're pretty dang photosensitive. |||||фотосенс

But scientists thought there might be more to the picture.

- Just like those early observers ||||спостерігачі

of diel vertical migration, we're using sound.

Light doesn't penetrate very far in the ocean ||проникає|||||

so when we try to go down with a camera

with a lot of lights, we're lucky if we see

a few arm lengths in front of us

but sound travels both further and faster in water

than it does in air and so we can get a really large scale

picture very quickly of what's happening with animals.

So we combined those sonar observations

where we send out a short pulse of sound and interpret

how it echos off the animals in the habitat ||отражается|||||| ||відлунює||||||

with low tech tools like nets but also with new techniques,

looking for evidence of the DNA

that these animals leave behind

in the water column, for example.

We kinda combine all these different lenses

to get a complete picture of what's happening

far away from what we can ever see

when we're sitting on a ship at the surface.

- Thanks to all this high-tech study,

scientists have figured out that DVM

is fueled by more than just sunlight changes. |підживлюється||||||

For instance, scientists studying zooplankton in the Arctic |||||||Арктиці

saw that during the long, dark winter months,

zooplankton responded to moonlight instead. |||світло мі|

So all of this new information has totally changed

the way scientists think about...

Well, it's changing what we know about plankton altogether.

Okay, so there's a different class of plankton

called phytoplankton. |фітопланкт

They're the ones that do photosynthesis

and actually give us most of the oxygen we breathe.

- There are some phytoplankton, some photosynthetic plankton

that also undergo vertical movements.

These are tiny, microscopic, plant-like organisms

that are drifting constantly with the currents

but they can control their vertical movement.

They can control buoyancy

and some of them actually have swimming organs

but typically we see that they're really close

to the surface harvesting sunlight

to photosynthesize during the day and then moving deep |фотосинт|||||||

in the water column at night in order to take advantage

of higher nutrient levels at deeper depths.

And so they're sort of shifting the balance

instead of worrying about food and predators,

they're worried about light

and nutrients that they need to grow.

- But that's not all.

It turns out that studying DVM could help us unravel

our own circadian rhythm,

the biological clocks that help our bodies keep time.

The term circadian comes from the Latin phrase circa diem, ||||||||близько до|

which translates to around a day.

And that's pretty appropriate, since circadian rhythms

control many of our day-to-day behaviors.

And most organisms that live on the earth's surface,

including humans, have a system of hormones

and parts of our brain, an internal biological clock

that helps control everything from sleep

to hunger to fertility.

If you're a living thing that lives on land, light

or the lack of light triggers the release of chemicals

that signal that it's time to do certain things.

Like, if you're a bee, these chemicals might send you out

to hunt pollen.

For plants, it might mean moving their flowers

in a different direction.

And for humans, when it gets dark,

our bodies start producing melatonin,

a hormone that helps us relax so we can sleep.

And when it's light, we produce less melatonin

which encourages us to stay awake.

So we know a lot about how these rhythms work

in land organisms

but when it comes to things that live in water,

circadian rhythms were kind of a mystery.

Like, do plankton even have them?

Or are they just little robots that follow light

like a moth to your porchlight? |||||портьерный свет |||||світло на

Well, in 2017,

researchers were studying zooplankton in the lab,

they noticed that not only do they move up and down

during a normal day-night light cycle,

they also found that they migrated

even when the lights were off all the time.

This means these specks of almost alien-like ocean life

might have a circadian rhythm just like we do.

But by far one of the strangest things we're learning

from studying vertical migration is that it might hold

one key to tackling humanity's biggest collective challenge;

climate change.

- Vertical migration plays a big role

in the biological carbon pump.

Organisms that photosynthesize at the surface

take carbon dioxide out of the atmosphere.

If that just stays on the surface water,

it just gets re-released back into the atmosphere.

But if it gets into the deep sea,

it can stay there for thousands of years.

And so by taking that carbon out of the atmosphere

and bringing it to the deep sea,

it is removed from the effects

of that carbon dioxide is having on climate change.

The ocean has done that.

It takes up every year, about 25% of the CO2 that we release

is absorbed by the ocean and sequestered. ||||||захоплений

Vertical migration is a really fast way to do that.

Animals come up to the surface, they eat those phytoplankton

that have taken up that carbon dioxide

and then they swim down to the deep sea

where they release their waste products,

where they are eaten, where they die.

- If we disrupt vertical aquatic migrations,

we could speed up the collapse of entire ocean food webs

and impact everything from our food supply to the climate. ||||||постачання|||

And all that makes studying the diel vertical migration

even more critical.

- I think vertical migration

is a really important engine for the ocean.

In fact, if there's a fish on your dinner plate,

it probably ate something that was vertically migrating. ||||||вертикально|

So not only is it helping the health of the planet

but it's providing a really key transfer mechanism

for food for humans as well.

I think it's just amazing to think about the world

in as many dimensions as the organisms in the ocean have to.

We're so used to being able to use our GPS

and know that if we come back to the same place,

it's going to look the same while in the ocean,

place isn't really a thing, right?

You stay with the water parcel and that gets swept around. |||||пакет з вод|||||

And if you try to stay in one place,

the characteristics of that environment

would change dramatically through time.

It's really hard to get your mind around

in order to start to think like these animals,

to understand the world that they live in.

- It seems kind of obvious when you say it out loud

but messing with the largest migration on Earth,

this colossal thing that happens every single night,

we could really screw up the planet.

We might even end up krilling ourselves. |||||крилинговать себя| |||||крилами|

(audience booing) |осуджуючи

I'm sorry.

Stay curious.

Actually, I'm not sorry, you're welcome.

Hey guys, this episode

was part of PBS's celebration of Earth Month. |||PBS|||| |||PBS||||

You thought Earth Day was good?

We got a whole month and I'd love to tell you

about a new series coming to PBS Terra

called "Untold Earth". |Невимовна|

The show is a collaboration with Atlas Obscura

and PBS Nature and it unpacks the mysteries

behind North America's strangest

most unique natural wonders.

There's a link down the description to the first episode

all about redwoods.

We hope you check it out

along with the rest of PBS's Earth Month offerings.

Thank you for watching and like always a huge thank you

to everyone who supports the show on Patreon.

We could not make these episodes without you.

If you'd like to support the show,

there's a link down in description

where you can find out more,

help support the channel

and find out about episodes before anybody else.

Plus you get a notification when we upload videos ||||notificação||||

so that you can be one of the first people to watch them

which helps other people discover the videos,

which helps other people discover the videos.

It's great.

Check it out, it's down there.

Bye.

- [Speaker] Can you get that through Instagram, huh? ||||||Instagram|

Warm up the pipes.