(tranquil music)

- [narrator] They are
one of the oceans'

long-distance travelers.

undertaking some of the
longest seasonal migrations

in the animal kingdom.

- [adam] Humpback
whales are found

in all the major
oceans on the planet.

- [lars] There are 14 different
distinct population segments

of humpback whales in the world.

(camera shudder clicking)

- [adam] The focus of our work

is on the Hawai i distinct
population segment.

- [stephanie] They breed
in the Hawaiian Islands,

and they feed in Alaska,
British Columbia.

- [adam] They are migrating
some 2,500, 3,000 miles

up to their feeding grounds

and then back down to
their breeding grounds.

- [lars] The humpback
whales get to Alaska

usually around early April,

and then they stay up there
until about late November

while they're feeding
all the time up there.

And then they turn around again

and usually start coming
back in Hawaiian waters

even in December,
and peak in February.

And then by end of March,

it's slim pickings
down here in Hawai i.

- [jens] It's called
a trickle migration

because we don't have
the entire population

coming down at once.

- [stephanie] And while they're
in the breeding grounds,

they are not eating at all.

They're just surviving
off of their blubber.

So it's very
energetically costly

to undergo that
migration each year.

- [narrator] Now scientists
in Hawai i and Alaska

have teamed up to
better understand

how this prolonged
period of fasting

is impacting the whales' body
condition and overall health.

- [andy] We now have
these very nuanced tools

that we can look not just at
the health of the population,

but of individuals.

It's allowing us to see
things we never did before.

- [lars] One of
the main questions

that we're trying to
address is pretty simple.

What does it cost to
be a humpback whale?

How much energy do these animals
spend migrating, breeding,

and those are the costs which
then they need to replenish

while they're up in Alaska.

- [martin] Unfortunately, we
still don't really understand

what a healthy humpback
whale looks like.

So for us to be
able to figure out

when a population is impacted,

we need to know what
the baseline is.

- [stephanie] Which
is quite important

because this whale population

is particularly
vulnerable right now.

In the last few years we've
seen changes happening

to the sighting
rates here in Hawai i

and our colleagues
in Southeast Alaska

reported the same thing.

- [kristi] They are certainly
sentinels of ocean health.

- [shannon] They can be
good bellwethers for change.

- [adam] Scientists have
studied humpback whales,

since the 1970s, behaviorally.

And so over the past
almost 50 years now,

we've learned a ton,

but these types of questions
that we are now trying to ask

are showing us how much
more we have to go.

- [lars] This is a really
exciting time to do research.

- [narrator] How do scientists

measure the whales'
natural fluctuations

in body size and overall health?

And what might that tell us
about their ability to cope

with future
environmental stressors?

(dramatic music)

- [announcer] Major
funding for this program

was provided by the
Batchelor Foundation,

encouraging people to preserve

and protect America's
underwater resources.

Additional funding was provided

by the Parrot Family Endowment
for Environmental Education.

(majestic music)

- [narrator] Southeast Alaska.

Remote islands covered in
dense temperate rainforest

give way to scenic
glacier-cut fjords,

that are bountiful
feeding grounds for

One group studying
humpback whales

in this rugged wilderness is
the Alaska Whale Foundation.

Its remote field station

is located in the
small community of

- Most of our work

has focused on humpback whale
populations here in Alaska

by studying both the
actual animals themselves

and the underlying prey.

- [narrator] From
April through October,

a small but dedicated team
of scientists and interns

use the field
station as their base

to conduct research in
the surrounding waters.

- [andy] Our study
area is a large portion

of Northern Southeast
Alaska; Frederick Sound,

Chatham Strait, Icy Strait,

and the nearest towns would be

Petersburg, Sitka, and Juneau.

We probably cover about 50%
of that area at this point,

and we're still expanding.

We have colleagues who are
working in various other spots.

- And this is one
of the key areas

that the humpback
whales come up to feed

throughout the summer
and fall months.

It's a very productive area.

- [andy] The diet of these
animals is about 80% krill.

- [martin] They're also feeding
on different forage fish

that are quite
important to the area.

Things like Pacific herring.

- Juvenile salmon, increasingly
at least in recent years,

capelin, sand lance, all
things that are small

and schooling or swarming
that occur in abundance.

- It does vary a little
bit throughout the season.

- [narrator] Over the course
of the summer whale season,

the team conducts four to
five multi-week surveys

as part of the organization's

comprehensive whale health
and abundance program.

- We're using these
point count surveys

to systematically sample.

This means sitting on
different designated points

for 15 minutes,
looking for whales,

counting every animal we see.

How far away is it,
what bearing is it?

And from that, we can
calculate, A, how many animals,

but B, where they're
situated as well.

Once these point
counts are finished,

we can then head
over to the whales,

and we try and get a photo
ID image of their flukes.

This will then tell
us who the animal is.

Is it a new animal to
the catalog that we have,

or do we know who it is already?

This tells us who is around
at what periods of time.

- [narrator] Scientists can
identify individual whales

by looking at their tail flukes.

Each fluke has a
distinct trailing edge

as well as a unique pattern

of black and white
pigmentation on its underside

that, like a human fingerprint,
is unique to that animal.

- We also want to get some
environmental information

on the ecosystem around them.

- [narrator] During
their surveys,

the scientists are
collecting water samples

so they can analyze
the nutrients

that are fueling the bottom

of this very
productive food chain.

They also deploy
devices known as CTDs.

- Which allow us to
profile the temperature

and salinity of
the water column.

So we're tracking
some of the sort of

physical and chemical properties
of the underlying ocean.

- [narrator] Knowing
the physical properties

of the water column enables
biologists to understand

the base of the food chain,

which can switch to
less nutritious plankton

as water temperatures rise.

In recent years, a
severe marine heatwave

in the north Pacific
had devastating impacts

on animals up and
down the food chain,

including the humpback whales.

Now the scientists'
goal is to link

what they see in the
underlying ecosystem

to the humpback's health.

- [martin] Takeoff.

- [narrator] As part
of a partnership

between the Alaska
Whale Foundation

and the University
of Hawai i at Manoa,

Ph.D. student Martin van Aswegen

collects body
condition measurements

of the humpbacks from the air.

- We try and sample
any and every whale

that we come across up here.

So we're using these drones

to noninvasively get over
the top of the whales

as they're surfacing.

And as they surface,
we can get a video,

a high-resolution image
of their body contours.

So we can see how
long the whale is,

but also how wide the animal is.

- [narrator] The drones are
equipped with flat lenses

and very precise
height estimators,

which make it possible
to translate the pixels

in an image into
exact measurements.

- And using some
software that we have,

we can measure the total
length of the animal,

as well as the width,

across 20 different
points on the body.

We can do this again
and again and again,

with the same animals
and different animals.

And this allows us
to see how quickly

these whales are gaining mass
throughout the summertime

while they're up here feeding.

Their job up here is essentially

just to gain as much mass
and weight as they can.

It tells us a little bit

about how productive
the system is for one.

And this is important

because we can look at
the variation on this

across different years,

but also looking at different
environmental variables

that may result
in this variation.

And that can be an indicator

of how the population is
fairing both within a season,

but also across multiple years.

Beautiful.

- And so, by incorporating
all this physical,

chemical, and biological
oceanographic data

and simultaneously looking at

how the population
are responding in

month to month, year to year,

we're hoping we will be
able to make those links

between whale health
and ocean health.

- [narrator] As the
whales migrate south

in the winter months,
so does the research.

- [martin] 3-2-1 takeoff.

- [narrator] Hawai i's
warm, shallow waters

make for an ideal place to breed

and give birth to
vulnerable calves.

(majestic music)

While in Hawai i, Martin
teams up with collaborators

with the Pacific
Whale Foundation

and the Marine Mammal
Research Laboratory

at the University
of Hawai i at Hilo.

- Pacific Whale Foundation
was founded in the 1980s

with the focus of learning
more about the humpback whales

that come to Hawai i each year.

- [narrator] Each January,
February and March,

the scientists conduct
regular whale surveys

in the leeward waters off Maui,

where most of the whales
tend to congregate

during the breeding season.

- The females are
coming to give birth.

The males are coming
to compete and breed

with those females.

The project is focusing
specifically on mother calf pods

as well as competition pods.

And so the first thing we
always wanna try and get

are those fluke identifications.

Once we know who
the individual is,

we can link that
back to archives

and begin to understand a bit
more about that individual.

Is it a male, is it a female?

How reproductive was that female

throughout its life history?

- We might know it's
age or it's minimum age.

If we have seen a
whale as a calf,

for example, and
then watched it grow.

- When it comes to photo
identification in Hawai i,

there's two really
long-term robust catalogs.

There's the one that
Adam Pack curates,

and there's the one that Pacific
Whale Foundation curates.

And if you put
those two together,

we have a really
good understanding

of the individuals that
come here to Hawai i.

And then Alaska Whale
Foundation of course

has its own Alaska humpback whale catalog.

- [narrator] To
further supplement

the sighting history
of the whales,

the team uploads the fluke shots

to a unique online database
called Happy Whale,

which logs sightings worldwide.

- Happy Whale is a website

that has an automated
fluke matching algorithm

built into it.

So when you upload your
photograph to Happy Whale,

it compares against
every other photograph

on the Happy Whale system
and returns results for you.

- A lot of people are
now starting to use

which now allows
us to track animals

across these large areas.

- [narrator] Once
photo ID images

of all the animals in the
pod have been collected...

- [martin] 3-2-1 takeoff.

- [narrator] Martin
launches his drone

to take videos of all
the animals from the air.

- And our focus with
mother and calf groups

is looking at that
energy exchange

between mothers and calves.

And so we know that mom
is providing the energy

for that calf solely.

- These mothers are under
extreme, energetic stress.

- So we expect
mother's body condition

to decrease and the calf's
body condition to increase.

What we're trying to
answer with the drone work

is how fast that
energy exchange happens

and how much of it happens
while they're here in Hawai i

and then how much
is still going on

when they're up in Alaska.

And so if we're
able to determine

exactly how energetically
costly that is

and how much time they
need here to do that,

we can begin to model or predict
impacts of climate change,

for example, on
humpback whales' ability

to complete important
life history cycles,

such as birthing and calving.

- [narrator] The
scientists also study

what are known as
competitive groups.

- These are, you know, my
favorite groups to encounter.

You have a lot more
whales in close proximity

and you have a female
that is ready to mate.

And so you have males
fighting or competing

for the position
next to the female.

And so you have a male that's
called the principal escort,

meaning he has the primary
position next to a female,

that's defending that position
against secondary escorts

that are coming
in to try and take

that primary position away

from the current
animal that holds it.

- The competition
pods are very dynamic

and the composition
is always changing

where whales will come
and join the group,

whales will leave the group.

- That was a calf,
fluke up dive.

- [narrator] Also part of
the team is Dr. Adam Pack,

a longtime whale researcher

from the University
of Hawai i at Hilo.

- Since 1976, when my
mentor, Lou Herman,

pioneered the scientific study

of humpback whales
in Hawaiian waters,

he and his students,
which include myself,

have studied the Humpbacks
and the behavioral ecology

both in Hawaiian waters
and in Southeast Alaska.

- [narrator] Once the team
has gathered the photo ID

and drone data,

Adam collects a small
skin and blubber biopsy

of each whale in the group.

- We do this using a technique
which is well established,

a cross bow, which
fires an arrow

with a little
stainless-steel tip,

that's sterile on the end of it.

Let her commit.

We will start
paralleling each whale

and waiting patiently
for that whale to come up

in a high arch dive.

We want to have the
biggest profile we can

of the whale's body.

And my goal is I want
to go about a foot below

the dorsal fin, plus or minus.

It basically bounces
off the whale

and extracts a small
sample of skin and blubber.

In most cases, the whale
just continues with its dive.

Occasionally a whale might
do it a little tail flick,

in those situations,

it might be like a
little mosquito bite.

- [narrator] To date,
Adam has collected

nearly 500 biopsy samples
as part of this project,

which are sent to Dr.
Shannon Atkinson's lab

at the University of Alaska
Fairbanks for analysis.

- One of the big areas
that we tend to focus on

is the endocrine system,

and what that really
is, is hormones.

Hormones are what
drives behavior.

And so these hormones, we
extract from the blubber

and then we run them
through tests in our lab.

They're really in two
different categories.

Some of them, we call
them the sex steroids

and they're related
to sexual activity,

sexual reproduction, everything
that has to do with sex.

We can start to look at
things like pregnancy rates

and whether the
pregnancy rate of animals

is going up or going
down, or is very stable.

- We look at
testosterone in males,

how does that
naturally fluctuate

over the course of the
reproductive season,

but also in conjunction
with the various behavioral

and social roles
these animals take.

- And so is there a relationship

in the testosterone
level of the males

that are at the
principal escort position

and those that are further
back that are just hanging out,

is there a relationship

with the amount of
aggression we see?

- [narrator] Shannon's
lab also analyzes

the whales' metabolic hormones.

- They tend to have more to do

with the body condition
of the animal,

the health of the animal,

in terms of its wellbeing
or its state of stress.

- As they are using up
these energy reserves,

including mothers that are not
only metabolizing their fat

for their own needs,

but also for the needs
of their newborn calf,

how is that being
translated into stress?

We really don't have a baseline

of understanding the physical
health characteristics

and the reproductive
health characteristics

of humpback whales,

so that we have something to
compare chronic stress to.

Once we establish that baseline,

then we're better
equipped to understand

what happens when these
animals experience

non-natural stressors,
or natural stressors

that have to do with
climate, like a warming ocean

that may negatively
impact food resources.

- [shannon] 1-9-6

- [narrator] A sub-sample
of the biopsies

goes to Dr. Kristi
West and her team

at the University of Hawai i
Health and Stranding Lab.

- We're specifically
looking at stable isotopes

in effort to better understand

the foraging of each individual.

- [narrator] Stable
isotope analysis

lets scientists trace elements

as they move up the food chain.

- [kristi] And we focus on
nitrogen as well as carbon.

And ultimately this is a
signal in the whales' tissue.

So in the skin samples
that are collected

from these live whales,

and we can match that
signal to prey sources

that these whales
may have foraged upon

prior to the collection
of the sample.

And we think that this
gives us the timeframe

of a month or more.

- [narrator] Knowing what
the whales have preyed upon

gives scientists an idea about
the health of the food chain.

- So it certainly has the power

to help us tease apart
what changes have happened,

in terms of looking
at their foraging.

And then of course,
that next question is

what drove that foraging
change in the first place

that may be negatively impacting
the health of the whales.

- [narrator] Kristi's team is
also developing a new method

of analyzing the fat
cells in a whale's blubber

to correlate their size

with the animal's body
measurements from the drone.

- This is an analytical tool

to try and really quantify
how much fat storage

does each individual
have on them.

We're looking for
those fat cells

so that we can identify
them and measure their size.

And then we ultimately
are measuring

maybe 100 of those in
any individual slide

to get a really strong
average of that fat cell size.

And then we are also using
software to calculate for us

the degree of connective
tissue in any given image,

as opposed to those fat cells.

So that we have an idea
of how much of that area

that we are examining
is represented by

which is probably only gonna
have really small fat cells,

versus a large number of
nice, robust fat cells

and just a little bit
of connective tissue

serving the purpose of holding
that tissue altogether.

- [narrator] Data from
stranded humpbacks

has shown that emaciated whales

tend to have much
smaller fat cells

than animals that have
a robust body size.

- So really exciting
to have a chance

to put the whole story together,

through working with such a
large and collaborative team

across the ocean basin.

- We certainly
rely on each other

to be able to provide
different datasets

to fill in gaps where we can,

in order to just keep working
on this puzzle piece by piece.

We're starting to get a diverse,

but long data set
that encompasses

And the idea is
to keep this going

so we can have a multi-decadal
dataset over time,

which is going to be
a lot more powerful.

- [narrator] Between 2018

and the end of the
2022 breeding season...

- Two more coming up.

- [narrator] Martin
captured approximately

6,300 drone measurements

of over 5,000 humpbacks
in Hawai i and Alaska.

This includes repeat sightings

of more than 120 individual
animals, in both locations,

within six months of each other.

- Some of the measurements

that we're getting
are quite surprising,

things like adults losing up to

28 inches of their body width
while on the breeding grounds,

for example, and
that's without a calf,

that's just a
regular mature adult.

But also the calves have
been really interesting,

because we can sample
calves in Hawai i

throughout the season.

They're typically
there for 60 days.

To be able to do it
a few months later,

once they get back to Alaska,

that's incredibly rare
and difficult to do

so those data points
are really valuable.

So for example,
some of the calves

that we sampled in
Hawai i initially

were 11 to 13 feet in length.

And about four months later,

they were about
28 feet in length.

And some of them were
about 900% heavier

in terms of the body
volume, which is incredible.

The amount of stress that
must put on the female

who at that point is 35% lighter

than she was a few
months earlier.

- Some of Martin's results
are showing that on average,

when a female is here in
Hawai i and lactating,

she loses about 100
kilograms per day.

So I weigh 80 kilograms,

so it's more than my
weight every single day.

- [martin] Mothers are the
rock stars of this population.

- [narrator] Martin's drone
measurements also reveal

that humpback mothers
with nursing calves

don't regain all
their lost weight

once they return to
the feeding grounds,

but instead they are
plateauing at best.

- In other words, all that
food she's been eating,

she's offloaded it to that calf
as it's becoming a yearling.

Now, when we look preliminarily

at the steroid hormone analysis,

what we see is
mothers of yearlings

have significantly greater

cortisol stress
hormone concentrations

than mothers of newborn calves.

That's exciting because
that piece of the puzzle

is marrying very well
with what we're finding

with the body condition

and what we see behaviorally
from these whales.

- [narrator] The scientists say

understanding the
natural changes

in the humpbacks' body
condition and stress levels

is critical in the face
of future climate change

and shifting prey availability.

- We're a lot more well
equipped to identify

when whales are under
stress in the future.

- These long-term
monitoring programs

and science projects are
really, really important,

particularly when it
comes to management.

- If we're able to monitor
the health of individuals,

we're very quickly able to say
if the population is healthy

and our oceans are healthy,

or if humpback
whales are unhealthy,

the oceans are unhealthy,

and we need to look
at what we can do

to reduce any potential
impacts that we're seeing.

- We know that the
ocean is going to warm.

And so we are
positioning ourselves

to be able to
respond more quickly.

- And in that way,

I think our work can
really make a difference.

(majestic music)

(tranquil music)

- [announcer] Major
funding for this program

was provided by the
Batchelor Foundation,

encouraging people to preserve

and protect America's
underwater resources.

Additional funding was provided

by the Parrot Family Endowment
for Environmental Education.