Blubber, Part 1

In this two-part series from Stuff to Blow Your Mind, Robert and Joe discuss the science of blubber and some of the ideas surrounding cetacean insulation.

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Episode Transcript

Speaker 1 (00:03):
Welcome to Stuff to Blow Your Mind production of iHeartRadio.

Speaker 2 (00:12):
Hey you welcome to Stuff to Blow your Mind. My
name is Robert Lamb.

Speaker 3 (00:16):
And I am Joe McCormick. And today on Stuff to
Blow Your Mind, we are going to begin a couple
of episodes on the subject of blubber. I am surprisingly
fired up about blubber. I don't know exactly why, but
I'm like acheing to talk about it.

Speaker 4 (00:31):
Well.

Speaker 2 (00:31):
I think a big part of it is that, if
nothing else, blubber is just a funny word. It's just
a funny sounding word. I had to look into it
a little bit before we proceeded here, apparently stemming from
the late fourteenth century blobber, which describes bubbles, bubbling, or foaming,
often pointed out like the Middle English for foam, and

(00:54):
this also influences the verb blubber, as in two blubber.
So yeah, at the very least, blubber is just a
funny word to think about and say.

Speaker 3 (01:05):
Does the word blob come from the same root as blubber?

Speaker 2 (01:08):
I believe it does.

Speaker 3 (01:10):
Wow, So it might not surprise you if you know
anything about marine mammal anatomy. To hear that, I started
thinking about Blubber to cover on the show because we've
come into the winter months here in the Southeastern United
States and I have felt that desire again to wrap
myself in coziness, to find barriers against the cold. And

(01:34):
this of course got me thinking about Blubber, which turned
my mind once again to one of my favorite weird
novels to quote and explore on stuff to blow your mind.
That is Herman Melville's Moby Dick. We've talked about passages
from Moby Dick on the show before, often related to
whale anatomy, but sometimes on other strange subjects. I know
we did a bunch of stuff about Moby Dick when

(01:57):
I did an episode with Lauren and Annie of of
the podcast Savor on Ambergris or Ambergrise uh, and we
talked about Moby Dick when Rob, when you and I
did some episodes on whale spout on like what exactly
is going on there when you see that you know,
the whale blast, what's coming out? And does it burn
the skin? Does it poison people? As alleged and Moby Dick.

Speaker 2 (02:20):
I like that you have singled it out as a
weird novel.

Speaker 3 (02:23):
Oh, it totally is weird.

Speaker 2 (02:24):
I think it is easy. It's given its its notoriety,
and you know, everyone has heard of Moby Dick, and
a lot of people have. If you haven't read it,
you've at least seen a film adaptation of it, hopefully
one of the good ones. You might miss the fact that, yeah,
it is very weird in many regards.

Speaker 3 (02:41):
You know, it's incredibly weird and what i'd say, one
of the weirdest books that people read in school probably.

Speaker 2 (02:47):
Yeah, yeah.

Speaker 3 (02:49):
Oh.

Speaker 2 (02:49):
We also talked about it briefly in Wrath of Khan,
our Weird House cinema episode, because of course it too
takes a hefty shot of Moby Dick.

Speaker 3 (02:57):
Oh, that's right, but of course relating to blubber specifically,
in chapter sixty eight of Moby Dick, the narrator Ishmael
meditates on the concept of whale skin and whale blubber,
which he calls the blanket. Now, as we've talked about before,
the whale facts and Moby Dick are of varying accuracy
when reconciled against modern science. Sometimes they're pretty spot on,

(03:21):
other times they're way off. Some of the main observations
in this chapter, as we'll discuss are correct, mainly in
that Ishmael observes that the whale's body is surrounded by
a thick layer of blubber, and that one of the
blubber's main purposes is related to insulation the retention of
body heat. That's not the only thing that blubber does

(03:42):
in marine mammals, but that's a big part of it.
It's one of the most important things it does. So
first he marvels at the incredible size and quantity of
blubber within the whale, which, in the example of a
single sperm whale that he's talking about, boils down into
one hundred barrels of oil. He says, one hundred bear
of oil from a single whale, and that's not even

(04:02):
the entire mass of its outer skin or integument layer.
And he says that that gives the mind a hint
of the quote enormousness of that animated mass overall. And
he also observes the texture and the makeup of the blubber,
which is quote something of the consistence of firm, close
grained beef, but tougher, more elastic and compact, and ranges

(04:27):
from eight or ten to twelve and fifteen inches in thickness.
He also remarks curiously when he's looking at the outer
skin of the sperm whale. He says that the sperm
whale's skin is quote all over, obliquely crossed and recrossed,
with numberless straight marks in thick array, something like those
in the finest Italian line engravings, which he later also

(04:50):
compares to Egyptian hieroglyphics. He especially makes the connection to
the mysteriousness of the hieroglyphics and the mysteriousness of the
marks the whale's body. I think we now know that
this is actually a common thing you do see on
the bodies of sperm whales, that they will have lines
or sometimes even circular scars over their bodies, which can

(05:11):
in part come from battles with the squid they hunt,
can come from running into things, butting, fights with other whales,
all kinds of scrapings and accidents, maybe sat yes, mating,
maybe other contact with fishing equipment or whatever. The whales
can get a lot of scars. And I love thinking
of these scars on the outside of the sperm whale

(05:32):
skin as like a mysterious language to be deciphered.

Speaker 2 (05:35):
Yeah, I love that.

Speaker 3 (05:37):
But then Finally he comes to marvel at the blubber
as a heat retaining adaptation within the whale, which he
kind of connects two thoughts about human character. So I'm
going to read a more extended passage here. Ishmael says, quote,
it is by reason of this cozy blanketing of his
body that the whale is enabled to keep himself comfortable

(05:59):
in all weathers, in all seas, times and tides. What
would become of a greenland whale, say, in those shuddering
icy seas of the north, if unsupplied with his cozy surtout.
Surtout is a type of coat from the time. By
the way, so his cozy surtout true. Other fish are
found exceedingly brisk in those hyperborean waters. But these, be

(06:22):
it observed, are your cold blooded, lungless fish, whose very
bellies are refrigerators, creatures that warm themselves under the lee
of an iceberg, as a traveler in winter would bask
before an infire, whereas like man, the whale has lungs
and warm blood freeze his blood and he dies. How
wonderful it is, then, except after explanation, that this great monster,

(06:46):
to whom corporeal warmth is as indispensable as it is
to man. How wonderful that he should be found at home,
immersed to his lips for life in those Arctic waters.
And then a little later he says, it does seemed
to me that herein we see the rare virtue of
a strong individual vitality, and the rare virtue of thick walls,

(07:08):
and the rare virtue of interior spaciousness. Oh man, admire
and model thyself after the whale. Do thou too remain
warm among ice? Do thou too live in this world
without being of it? Be cool at the equator, Keep
thy blood fluid at the pole, like the great dome
of Saint Peter's, and like the great whale. Retain o man,

(07:31):
in all seasons a temperature of thine own beautiful.

Speaker 2 (07:35):
I love it. I especially want to get back to
that immerse to his lips for life in those Arctic waters.

Speaker 3 (07:42):
Later on in this episode, now I mentioned that this
chapter I was just quoting from is called The Blanket
Chapter sixty eight. The blanket. The blanket referring to the
coating of blubber around the whale's body. There is actually
a much earlier part of the story which struck me
as abstractly and yet powerfully can to this chapter, and
this earlier part is not about whale anatomy at all,

(08:05):
but about a literal blanket. And it seems also related
somehow to the seasonal mind state I've been in that
got me thinking about blubber. So this is chapter eleven,
much earlier. It's called night Gown, and the context in
the story is that because of overcrowding at a boarding
house on Nantucket, Ishmael he's just arrived there and he

(08:25):
has been forced to share a room, and not to
share a room, to share a bed at the boarding
house with the Polynesian harpooneer quek Weeg. And he's initially
much annoyed by these circumstances, but then after some reflection
and some experiences together, Ishmael comes to not just tolerate,
but admire and even adore quek Weeg, and they become

(08:46):
best of friends, in Ishmael's words, a cozy, loving pair
on their honeymoon. So in the Nightgown chapter, Ishmael writes
of sharing a bed in a blanket at the boarding
house with quik Weeg. He says, first they try to sleep,
then they're not able to sleep. And then finally, he says, quote,
we became very wakeful, so much so that our recumbent
position began to grow wearisome. And by little and little

(09:09):
we found ourselves sitting up, the clothes well tucked around us,
leaning against the headboard, with our fore knees drawn up
close together, and our two noses bending over them, as
if our knee pans were warming pans. We felt very
nice and snug, the more so since it was so
chilly out of doors, indeed out of bedclothes too, seeing
that there was no fire in the room. The more so,

(09:31):
I say, because truly to enjoy bodily warmth, some small
part of you must be cold. For there is no
quality in this world that is not what it is merely.
By contrast, nothing exists in itself. If you flatter yourself
that you are all over comfortable, and you have been
so a long time, then you cannot be said to

(09:53):
be comfortable anymore. But if, like Queequeg and me in
the bed, the tip of your nose or the crown
of your head slightly chilled, why then indeed, in the
general consciousness you feel most delightfully and unmistakably warm. For
this reason, a sleeping apartment should never be furnished with
a fire, which is one of the luxurious discomforts of

(10:13):
the rich. For the height of this sort of deliciousness
is to have nothing but the blanket between you and
your snugness and the cold of the outer air. Then
there you lie, like the one warm spark in the
heart of an arctic crystal.

Speaker 2 (10:29):
Beautiful? Beautiful. Do you think that the two characters were
talking about any of this as they said in bed? Oh?

Speaker 3 (10:36):
Maybe, I don't know. I don't remember at this point
in the story how extensively the two characters are communicating
across it. I don't remember what to what extent. There's
a language barrier at the beginning of their friendship.

Speaker 2 (10:46):
Yeah, it could have been said, if I could have
just said, Hey, isn't this delicious? I'm glad we don't
have a fire.

Speaker 3 (10:51):
Yeah, But no, I think there really is something to
that that there is a way that it is much
cozier to be warm under a blanket in a cold
room then to be under a blanket in a warm room.
I mean, in a way that's almost obvious.

Speaker 2 (11:05):
But yeah, No, I'm a big blanket fan. If it's
too hot, I'm a little bit sad that I don't
get to cover up with blankets more. Yeah, and then
when it's too cold, I'm just sad in general. So
the one warm stark, Yeah, I know what he's getting
at here.

Speaker 3 (11:21):
But I thought that this was beautiful and insightful, and
to some extent it makes me think also of the
anatomy of the whale, thinking of the whale's body as
a blanket, the idea of creatures that carry their blanket
with them into the icy waters. And if you apply
the same reasoning, you know, as we'll discuss in the
anatomy of the whale, the whale is not coated in

(11:41):
every single part of its body by the blubber. So
I wonder what the sensation of the whale is. You know,
it has blubber mostly all around its body, but maybe
not fully in the flippers or something. So does it
have those little exposures to the iciness around it? What
does it feel like to the whale? Does the whale
have that sensation in the cold it feels with the

(12:03):
flippers or some little parts of its body of the
one warm spark in the heart of an Arctic crystal,
except it doesn't have to wrap itself in the blanket.
The blanket is under its skin.

Speaker 2 (12:12):
That's a great question. Yeah, I mean, another thing about
blubbers we'll discuss is that blubber is not uniform thickness
over the entire body of the whale. It's going to
vary in thickness depending on where you're looking at. So
I know it's a human thing, I guess, But anytime
I see a creature that has evolved to thrive in
the cold corners of the world, it doesn't depend on
its technology to do so. Like humans, I always just

(12:35):
kind of, on some like non thinking level, assume that
they're just really called and miserable all the time. But
of course that would be it'd be that's rather unreasonable
with me.

Speaker 3 (12:44):
Yeah, I wonder if that's the equivalent of a tropical
lizard looking at us, being at you know, seventy two
degrees in the shade, and thinking we must be miserable.

Speaker 2 (12:52):
Yeah.

Speaker 3 (12:52):
So anyway, and the rest of the series, we're going
to be exploring blubber as biology and also some things
about blubber in hue and culture.

Speaker 2 (13:00):
Yeah, most of that will probably be in the second episode. Yes,
this episode will be more about what blubber is and
what it is to a specific whale species.

Speaker 3 (13:10):
Yeah, what it is and what it is not.

Speaker 2 (13:12):
Yes.

Speaker 3 (13:12):
So the best source I found rob in providing a
scientific overview of blubber is actually an extensive, in depth
entry in the Encyclopedia of Marine Mammals from two thousand
and nine from Academic Press. This article is by a
well known marine biologist named Sarah J. Iverson, who is
affiliated with Dalhousie University in Nova Scotia. So I thought

(13:34):
maybe we could start off by going through this entry
talking about some of the points that Iverson raises and
branch out for discussion at various places as we go along.
All right, so what is blubber. Blubber is fat, yes,
but it is not just fat. It is not just
like the adapose tissue of other mammals in the world.

(13:55):
Blubber is, in Iverson's words, a quote dense, vasculared layer
of fat beneath the skin. So it is a special
type of fat tissue that is a characteristic trait of
marine mammals. It is found only in the mammals of
the sea. There are not really fully land dwelling animals
that have blubber, so all cetaceans meaning whales, porpoises and dolphins,

(14:21):
all cyrenians like manatees and dugongs, and all pinnipeds meaning
seals have blubber. Iverson notes a couple of exceptions of
marine or semimarine mammals. Things you might think of as
marine mammals or semimarine mammals that don't have blubber. Polar
bears and sea otters don't have blubber strictly defined, though

(14:42):
obviously they do have and rely on fat. Polar bears
tend to store a lot of subcutaneous fat, which is
used to insulate the body, but it doesn't have the
special structural and chemical features found in blubber. It's more
like regular terrestrial carnivore fat, but they do keep a
lot of on their body when they can to help
stay warm. Blubber is an incredibly important adaptation for marine mammals.

(15:07):
It makes marine mammal life possible, and in some species,
at particular stages of life or times of the year,
blubber can make up fifty percent of the animal's total
body mass. So you know some whales you meet are
half blubber. In part, blubber serves the same purpose as
fat in other organisms, so it stores food food energy

(15:30):
that can later be burned to support the body's energy
needs when food is scarce. But it also does other
important things for marine mammals. Most importantly, probably blubber is insulation.
It protects marine mammals body heat against the often extreme
cold of their watery environments, and it does so in
particular interesting and dynamic ways. We'll talk about that more

(15:53):
as we go on, but blubber also aids in buoyancy
and has interesting functions in help with locomotion, maybe in
some cases streamlining the body in the water, in other
cases even serving as a kind of spring. We can
talk more about that later. And also you can learn
a lot about a marine mammal by looking at its blubber.

(16:14):
At the species level, you can learn about its evolutionary
history and environmental specialization, and at the individual level, you
can learn a lot of things about like what this
animal has been eating and where it's been foraging by
looking at its blubber.

Speaker 2 (16:28):
Yeah, and another factor that I think we already kind
of alluded to in terms of like the scarring on
a whale is that blubber does provide some level of protection,
some level of armor, which can can seem a little
counterintuitive at first, because we think of an animal's armor,
we think of hard armor. We think of hard, unfeeling
protection between the organism and its many threats, And obviously

(16:52):
blubber is not quite a hard shell. But on the
other hand, it can sustain a fair amount of damage
from an animal's environment, so it does have to a
limited degree some sort of an armor role here as well.

Speaker 3 (17:08):
Yeah, and even in non marine mammals, there are cases
where fat plays an important role in protective cushioning, you
might say, even if it's not like, you know, not
like plate armor, but it does play a protective role
in some types of cushioning basically patting. So getting into

(17:34):
the structure of blubber. Blubber is subcutaneous fat, meaning that
it's stored around the outside of the body, just under
the skin. And this is in contrast to visceral fat,
which is stored deeper in the body cavity surrounding the organs.
Blubber sits just under the skin, kind of loosely enveloping

(17:55):
the underlying layer of muscles. And as I mentioned, blub
is not just fat. It is this special type of
fat tissue which is shaped by evolution for a very
special purpose, primarily that of a dynamic thermal insulator. So
in most marine mammals, the blubber layer is a continuous

(18:18):
covering for almost the entire body, with some exceptions like
the appendages. Often the flippers won't have blubber. Though it
does tend to cover the whole body, it doesn't cover
it evenly everywhere, so the thickness and structure of the
blubber layer differ on different parts of the body for
reasons we'll probably get into later.

Speaker 2 (18:39):
Now.

Speaker 3 (18:39):
While blubber is not just regular fat tissue, it is
still basically fat tissue. It's similar to regular fat, also
known as adipose tissue, in that it is made mainly
of fat cells called adipocytes. Atopocytes are energy storage cells
that first form in an immature ste age without fat

(19:01):
or without much fat stored in them. They're initially mostly
protein and water, and then as the animal is able
to take in more food energy than needed to sustain
its metabolism, the extra energy is stored as lipid molecules.
In the now mature fat cell as atiposites accumulate these
liquid droplets for storage. They swell up in size, so

(19:24):
adipocytes are very stretchable cells. Their cells that can grow
and shrink as needed. When they fill up with fat,
they stretch and grow. When fat stores are depleted, they
can shrink back down to size.

Speaker 2 (19:36):
Yeah. Humans, as humans, we tend to have a very
toxic relationship just with the word fat, almost to the
point where it colors or creates a barrier to understanding
its necessity for an organism, or or at least that's
the way I have often been found in anytime I'm
reading about like the actual purposes of fat, fatty tissue,

(19:57):
I'm like, oh, of course this is actually super important.
But we're often just coded to, you know, buy the
media and culture to have to feel a certain way
about even the idea of a fat in our body.

Speaker 3 (20:10):
Yeah, I guess I can see that. Well, I would
encourage you out there to try to break that shackle
in your brain, like not to associate, you know, any
kind of negative cultural ideas or whatever with the idea
of fat biology. Like, fat is really interesting tissue and
it's really important, you know, it's almost I would almost
say it's like the biological equivalent of wealth in a way.

(20:31):
It's like, you know, something that can be accumulated to
be used later and serves important purposes along the way.
So these fat cells, they can they can grow and
shrink as needed, and in most atipos tissue, these fat
cells are packed densely together and held together by what's

(20:51):
called an extracellular matrix, a kind of honeycomb mesh or
three D net made out of things like collagen fibers.
Collagen is the structural protein found in animal skin and
in connective tissues. A lot of cooks will be familiar
with collagen because structural collagen is a major part of

(21:11):
what makes certain cuts of meat tough, Like tough muscles
usually have a lot of collagen connective tissue in them,
and so these are the cuts that typically you have
to slow cook. You want to cook for a long time,
maybe with moist heat, and that type of treatment tends
to turn these tough cuts of meat with a lot
of collagen tender. It makes them tender because the collagen

(21:33):
breaks down and turns into gelatin, giving the final product
a soft texture. This is part of what sets blubber apart.
Blubber has significantly more of this structural material than most
adipose tissue in the animal kingdom, more collagen, more elastic fiber.

(21:54):
And for this reason you can kind of think back
to the description in Moby Dick of the blubber as saying,
you know, it's kind of like firm, close grained beef,
but he describes it also as tougher, as elastic and compact.
There's something dense and springy about it. It's just it's
tough stuff. And I think a lot of this probably

(22:14):
comes from this extra collagen and elastic content. I expect
we'll get more into this in part two when we
talk about blubber as a food item, which it is,
especially for people living in the polar regions. But I
would suspect because of this extra collagen and structural fiber
that blubber is a good bit chewier and tougher than
most animal fat. Maybe we'll have to revisit that next time.

Speaker 2 (22:37):
Yeah, but certainly in the meantime, for any of you
out there who have personal culinary experience with blubber, go
ahead and write in.

Speaker 3 (22:46):
Totally yes please. And by the way, Iverson also in
this entry mentions the textural difference in blubber between blubber
and regular fat, not in the context of blubber as food.
She writes that blubber tends to have a quote firm, tough,
and fibrous character, distinct from most other animal fats, and
this toughness and strength gives blubber a lot of its

(23:08):
important adaptive qualities for the marine mammal. Another common structural
distinction that biologists make about blubber as opposed to other
adipose tissue is that it is highly vascularized. In Iverson's words, quote,
blubber also contains numerous blood vessels and specialized shunts called

(23:29):
arteriovenous anastomoses or avas, which allow larger and swifter blood
flow than would be possible through the capillaries alone and
are important to the thermoregulation process. So this is the
really key thing about blubber as an insulation method. It's

(23:50):
not just static insulation. Say like a beer cooler. You know,
a beer cooler is really it's great. Beer cooler provides
great insulate You can put cold things in, It'll stay
cold a long time, even on a hot day. You
can put hot things in it. They'll stay hot for
a long time. You know, it's great, but how insulating

(24:11):
the cooler is does not change unless you open the lid.
Blubber is adapted to selectively either insulate the body and
keep the blood flow and thus heat exchange to the
outside minimal, or on the other hand, to allow rapid
voluminous blood flow through the fat tissue and near the skin,

(24:31):
including by connecting veins directly to arteries, or I think
these would be slightly smaller vessels like arterials and you
know the next step down from veins and arteries directly
connecting those things. And this is important because it gives
the animal a lot of control over its internal body temperature.

(24:52):
The blubber is an insulator that protects body heat against
the cold water when needed, and then allows the mammal
to wrap it dump excess heat into the water when needed,
for example during exertion to make more vigorous activity possible
without overheating, or just when it goes into hotter, warmer waters.

Speaker 2 (25:10):
So this is going to be an outrageous overstatement of
the obvious, but sometimes I think these can be helpful,
like it is helpful to compare the blubber to a
blanket or a winter coat. But a winter coat or
a nice blanket is not a part of our body. No,
the blubber is a living part of the creature's body.

(25:31):
It is at once the thing it is using to
maintain its temperature and also the flesh that is being maintained.

Speaker 3 (25:38):
Yeah, it's like if a coat were part of your body,
and you could flip a switch to make the coat
either make you hotter or make you colder. Now, this
is another thing we will explore more as we go on,
but it's important to note that there are huge variations
in blubber thickness among marine mammals. I'm not sure if
the numbers that Melville gives in mobi deck about the

(26:00):
average thickness of a sperm whales blubber layer are correct,
But I don't know. Maybe he's in the zone, but
I have questions about that. But there is at least
large variability between species and between individuals. So as animal
bodies get bigger, of course, it tends to be the
case that volume increases more rapidly than surface area. This

(26:25):
is sometimes known as the square cube law in animal
body sizes, and as a result, larger species tend to
have much thicker layers of blubber, so some examples given
by Iversen in this entry are that you might get
arrange for like seven to ten centimeters of blubber in
a lot of adult seals, and then up to twenty

(26:46):
to thirty centimeters in fin whales, and then up to
fifty centimeters of blubber in the bowhead whale, which I'm
to understand is one of the most shocking and amazing
blubber carriers in nature. Maybe the raining champion. I think
we're gonna you've got some stuff about the bowhead whale,
don't you, Rob.

Speaker 2 (27:04):
Yes, we'll definitely be coming back to the bowhead whale
here in a bit. Now, I do want a note
real quick that in the different sources we were looking
at for this episode, we did find that sided blubber
thickness for specific species of whale can vary quite a bit.
And I'm to understand this depends on what sort of

(27:24):
criteria you're using for measuring of the thickness, not so
much that like this source is wrong and this source
is right right.

Speaker 3 (27:32):
So Iverson in this entry says that like, the bowhead
can be up to fifty centimeters of thickness. I don't
know if that's like at the absolute maximum the thickest
place or something, or if that's referring to an average.
But I think you had the book by Karwadine that
cited a lower figure but still a huge amount of blubber.

Speaker 2 (27:49):
Correct. Yeah, so either in either case, the bowhead whale
is the best. If you will, it is the most
bloody best. And we'll, yeah, we'll come back for a
little more on the bowhead because I think it will
be illustrated to get into to get to know the
most blobbery whale, and in so doing learn why it
is so blubbery.

Speaker 3 (28:08):
Yeah. Another thing that's amazing about these animals with these
thick blubber layers is how rapidly it can accumulate in
like a newborn marine mammal as it nurses. Iverson talks
about this, this idea that newborn seals have very little
blubber when they're born. They instead, the newborns usually rely

(28:29):
on fur for insulation, fur or maybe a fine type
of mammal hair found on newborns called lenugo, and these
baby seals cope with their lack of blubber by simply
delaying entry into the water. So you know, most baby
seals are born on land or born on ice, and
they'll have to wait until sufficient fat stores are built

(28:51):
up before they can dive in and go for that
wet life. But the blubber accumulates fast, So Iverson mentions
the example of a newborn harp seal or of Foca grenlandica,
in which blubber is only on average about six percent
of body mass when the seal is newly born and

(29:13):
the blubber is only made of about twenty percent fat,
and then after a mere twelve day lactation period, the
baby seals are often up to fifty percent blubber by
weight and the blubber is ninety percent fat, So six
percent of the body to fifty percent of the body
in twelve days. And you can see the opposite during
times of fasting when adults are separated from food, for

(29:36):
example nursing mothers. We can talk about that in a bit.
When adult marine mammals can't get food, fat stores rapidly deplete.
So what types of lipid molecules do you find in
marine mammal blubber. Well, marine mammal fats are mostly made
up of fats that these animals get directly from their

(29:58):
food sources, including long chain polyunsaturated fatty acids or PUFA,
and what Iversen calls quote unique fatty acids produced at
lower trophic levels of the marine ecosystem, meaning fats from
lower down the ocean food chain. That's the majority of it.
But marine mammals can also make their own fat. They

(30:20):
can synthesize fat molecules from excess amino acids in the diet.
I think they probably could make fat out of carbohydrates
as well, but the diet of a marine mammal is
extremely low in carbohydrates. Usually they're doing that Atkins diet life.

Speaker 2 (30:37):
Yeah, in many cases, but certainly with the maleene whales,
we're talking about the consumption of a lot of tiny
oceanic organisms.

Speaker 4 (30:43):
Yeah.

Speaker 3 (30:54):
But anyway, I think we need to come back to
the idea of blubber as thermoregulation, because this is a
big deal. This is a big part of the evolutionary
function of blubber. In general, fat is an insulator. It
slows the exchange of heat. And I've read about some
fun looking experiments designed for kids just to illustrate this.

(31:17):
I kind of want to do one with my daughter.
I didn't have time to do it before we did
this episode today, but maybe I'll get around to it soon.
So one of these experiments is called the Crisco glove
or the blubber glove test. So the way it works
is you get a bucket of ice bucket of ice water,
and then you make a couple of mittens out of
ziploc bags. So one is going to be your control mitten.

(31:40):
That's just two bags, one bag inside of the other
with nothing in them, and then your hand is inserted
into the inner bag and then the other pair of
bags is your test mitten. So your hand goes into
the inner plastic bag, and then that bag goes into
a second plastic bag with a layer of vegetable shortening
in between the two bags. And then the idea is

(32:03):
when you dip both hands into the water, you will
feel the difference. The layer of shortening in the test
bag insulates your hand and keeps it warm against the
cold water, while the hand in the control bag will
rapidly lose heat in the ice water and start to
feel very cold.

Speaker 2 (32:21):
Yeah, I bet kids love this experiment. It has all
the hallmarks of a great kids science experiments. It has
sliminess and goofiness, it has immersion in another substance. Yeah,
I'm a little shocked. I'd never heard of it till now.

Speaker 3 (32:35):
Yeah, and you know, it's a great illustration of this principle.
That's not just about blubber and marine mammals. Marine mammals
are not the only animals that use fat as a
form of insulation against the cold. There is a common
adaptation throughout the animal kingdom, but marine mammals face some
specific challenges when it comes to thermoregulation. First of all,

(32:57):
they live in the water, and cold water remove heat
from the body more rapidly than air of the same temperature.
If you doubt this, just try it. Just feel the
difference between standing naked in a room where the air
is sixty degrees fahrenheit and then standing naked in sixty
degree fahrenheit water. The difference is unbelievable. It is starting.

(33:20):
The former is probably going to be a bit uncomfortable,
depending on your preferences. The latter is shocking. It will
make you gasp.

Speaker 2 (33:28):
Yeah, I've conducted this very experiment at the local YMCA
pool before.

Speaker 3 (33:33):
Oh, does it get that cold?

Speaker 2 (33:35):
There and on. Sometimes it does, so it generally it
would mean that there's been a malfunction with the pool
heaters or I mean, that's the most extreme case. But
I've also found that if there's like a rapid change
in temperature, like we go from a reasonably warm day
to suddenly it's winter weather, there's going to be a
little lag sometimes in the pool catching up. Ooh, so yeah,

(33:58):
those are the mornings. So mainly they heat or failure
days where you're really shocked when you jump in.

Speaker 3 (34:04):
Yeah, so, same temperature, but the colt but the water
at that temperature is so so much more of a
shock to your body. Water has a thermal conductivity about
twenty five times that of air, so it's just able
to remove heat from your body so much faster. And
when you are surrounded by air, you also usually benefit

(34:26):
from a thin layer of warmer air that just hovers
around your skin. Warmed by your body, this small layer
of warmer air provides some insulation for you in itself.
No such luck really in the water. The water absorbs
your body's heat directly to whatever stint. There is a
warm layer of water around your body. When you're in

(34:50):
the water, it's microscopically tiny and does not really do
anything to help keep you warm. So you just out
of luck there.

Speaker 2 (34:58):
Your only help is going to come the form of
bodily exercise. Are getting dry, yeah, or getting out yeah,
the transitioning to the hot tub for sure.

Speaker 4 (35:08):
Yeah.

Speaker 3 (35:08):
So cold water is just so much more unforgiving than
cold air. And so that's one thing. They're in the water.
The other thing is marine mammals, like all mammals, are
homeothermic indotherms. They produce their own body heat, and their
bodies need to stay warm or they will rapidly lose
functionality and die. They are not like there are animals

(35:30):
that whose body temperature can fluctuate much more throughout and
the animal will be okay. You know, homeothermic endo therms
are not like that. The water is a harsh place
for a homeothermic endotherm to live.

Speaker 2 (35:44):
Yeah, And Malvell alludes to this wonderful in that passage
you're at. Yeah.

Speaker 3 (35:49):
So to get around this, marine mammals, they've got several adaptations.
One is size. Marine mammals are larger on average than
terrestrial mammals. Even the smallest marine mammals are pretty big,
especially when you think about the actual average size of
terrestrial mammals. I mean, there are so many extremely tiny

(36:10):
terrestrial mammals. I haven't calculated it, but I would guess
the average size of a terrestrial mammal is like a
large rat or something. But marine mammals, the smallest ones
are still fairly big by land mammal size. And this
is evolution taking advantage of the square cube law. Again.
As animal bodies get bigger, volume increases more rapidly than

(36:32):
surface area, and animals lose heat to the environment through
their skin through their external surface area. So the internal
body volume makes and holds the heat, and then the
surface area, which decreases in proportion to that volume as
the animal gets bigger, is what loses the heat. Thus,
bigger body, greater relative heat retention.

Speaker 2 (36:54):
Yeah, and just a one more note on the largeness
of marine mammals, I mean, the biggest of the marine mammals,
the blue whale is not only the biggest whale and
the biggest vertebrate and mammal alive today, it is the
biggest vertebrate and largest animal known to have ever existed.

Speaker 3 (37:11):
Yeah, it's a body plan that works in the water.
Big bodies help you stay warm in the cold water.
But the size is one thing. I Everson notes that
then the other thing, of course, is insulation. Now, blubber
is not the only form of insulation used by marine mammals.
In some cases, these animals rely on fur, which tends

(37:32):
to work best in air, specifically because fur works by
trapping one of those insulating layers of air around the body,
so it traps air as insulation. But in cases where
fur would be less effective, like for animals that live
underwater all the time, blubber is going to be the
better option, especially because blubber works in both air and

(37:55):
in water. So in animals that live in the water
and then come out of the water, like some seals
and so forth, blubber is still going to be helpful
because it works in both places. Interestingly, some marine mammals,
like sea otters, are able to use fur as insulation
even in the water. And I got interested in why
this is. It seems like this is because their fur

(38:19):
is so good at trapping air. It can actually carry
an insulating layer of air with them when they dive.
So they go into the water and they take a
little bubble with them that's trapped in their fur. It
seems like this doesn't work, maybe if they dive too deep,
where water pressure will compress or push out the bubbles
of air and the insulation will be lost. And this

(38:42):
is probably why you only see the preference for fur
over blubber retained in marine or semimarine mammals like otters
and polar bears, which spend significant time in the air
up on the land or on the ice and don't
need to dive too deep or for too long. As
I talked about earlier, bluffer is an amazing adaptation for

(39:03):
heat control because it is not a passive static form
of insulation. It's dynamic and it can change its insulating
properties as needed in the moment, particularly by changing how
it channels blood flow. So when warm arterial blood from
the center of the body flows out toward the skin,
it loses heat to the surrounding water and cools the body.

(39:27):
When that arterial blood is kept away from the skin,
it retains heat. And because blubber is so vascularized, it
can switch this heat exchanging blood flow on or off
depending on what the animal needs. So in cold water
it can keep the blood further inside, keep it away
from the skin, and in warmer water or when the

(39:49):
animal is working out, it can open up the vessels
and shunts and allow the blood to dump heat into
the surrounding water through the skin. Unsurprisingly, given the we've
already talked about, marine mammals that live at higher latitudes
or swim in colder waters tend to have thicker blubber
for their body size, and the smallest cetaceans are usually

(40:12):
not found at the highest latitudes.

Speaker 2 (40:15):
You need extreme bodies for extreme environments.

Speaker 3 (40:18):
Yes, Now, one more thing I want to mention before
we get into your bowhead example, is another thing iverson
goes into, which is the specific role of blubber for
energy storage in marine mammals. Of course, you know, energy
storage is one of the main purposes of fat across
all the animal species that use it, but it has

(40:40):
a special role for marine mammals, especially in species that
migrate across great distances, using one environment for forage during
a fattening season, and then a different, sometimes far away
environment for important parts of their reproductive cycle. For example,
billen whales that travel to high latitudes in the summer

(41:03):
for feeding opportunities because of summertime booms and their planktonic
food sources at higher latitudes, and then we'll travel down
into warmer waters to give birth, to lactate and rear
their newborns.

Speaker 2 (41:17):
Gray whales are a great example of this, and wescuss
them in previous episodes.

Speaker 3 (41:22):
That's right, Yeah, so I think you observed grey whales
off the Pacific coast of Mexico.

Speaker 2 (41:28):
Is that right? Yes? I did. This was very much
they're breeding grounds.

Speaker 3 (41:33):
Yeah, that's right. So this is where they're raising their
young and then when season changes, they would travel back
up to around Alaska off the you know, the western
coast of North America for feeding opportunities. And even when
great global migrations are not involved, reproduction and marine mammals
often takes these animals away from feeding opportunities, for example,

(41:55):
winter dinning for the birth and nursing of cubs and
female polar bears. And this is especially interesting because of
the increased metabolic demand on female mammals to produce milk
after birth. So you know, after the mammal gives birth,
the mother's body is working overtime to synthesize rich, highly

(42:17):
caloric nourishment for the newborn. In most mammals, the mother
needs to draw on fat reserves and feed herself externally
during this period to lactate enough for her young. But amazingly,
some baline whales and large seals are able to nurse
their young without eating hardly at all, drawing almost entirely

(42:41):
from blubber reserves, and this is very unusual in nature,
Iversen writes. Quote in species that fast through lactation, females
switch almost completely to a fat based metabolism. For instance,
during a sixteen day lactation period, a gray seal female
draws ninety seven percent of the energy supplied to her

(43:03):
pup solely from her blubber stores. Wow and note that
the mother's blubber reserves during gestation will also dictate how
much blubber the pup is going to be born with
and then from here. Blubber also still plays an important
role in reproduction in the development of the young for
the pups because the blubber that they've gained during nursing

(43:26):
and that they're born with will sustain them after nursing
is over and until they're able to feed themselves. Blubber
Iverson notes is also an important reserve of internal water.
I never really thought about this but she gives the
example of gray seals during lactation. The mother seal is

(43:47):
going to be losing a lot of water through milk
production and is fasting on land to feed her pups,
so she's not able to replenish water stores externally. Extra
water comes from the oxidation of fat reserves in blubber
for metabolism, because when you burn fat inside your body,

(44:08):
water is a natural byproduct of that chemical reaction. This
is called metabolic water. So metabolic water is produced, and
then that provides water that the mother mammal needs. Now,
I want to note that in this entry, Everson also
gets into a lot of other interesting stuff about the
role of blubber and locomotion, buoyancy, movement, and other things.

(44:30):
We might talk more about those topics in the next
part in this series, but we want to definitely have
time today to talk about the bowhead whale.

Speaker 2 (44:36):
That's right, yeah, And I think it'll be a helpful
exercise here to take everything we've discussed so far and
then look at a specific example of a high blubber
species and see how things begin to line up. And
as referenced to earlier, I got this information from the
Handbook of Whales, Dolphins and Porposes of the World by
Mark Cardine. An excellent book for a anyone who just

(45:00):
wants to read about whales at home, or if there's
any possibility that you'll get to see one out in
the world going on any kind of like a whale
sight seeing tour, you know, And these are available all
over the place. It's worth having a copy of the book.
It's it's mobile. I've lent it to friends who have
gone on cruises before. It's a great read, lots of illustrations.
It informs you and also helps you in identifying what

(45:24):
you're looking.

Speaker 3 (45:24):
At in the wild.

Speaker 2 (45:36):
So we've already you know, mentioned you know what blubber is,
who has it? We've also mentioned, you know, what are
the biggest blubber containing animals out there. Obviously the blue
whale is going to be the biggest blubber animal. But
just because you're the largest blubber creature out there, it
doesn't necessarily mean you're the animal with the most blubber

(45:57):
or the most blubber you know, for your body. The
true blubber superstar is not the enormous blue whale. It's
not the fin whale, it's not the mighty sperm whale,
but it's rather the whale species it's often ranked fifth
in overall size, and that is the bowhead whale.

Speaker 3 (46:15):
I just looked it up because I wanted to make
sure I was picturing the correct whale in my mind.
And the bowhead whale is going to be the one
that has some sort of bone structure or structure in
the head above the sort of curve of the mouth
that looks like a hump. It almost looks like a
kind of bump in the nose, but it's on top
of the whale's head up above the eyes.

Speaker 2 (46:37):
Yeah, yeah, these are These are big, girthy whales, up
to eighteen meters nearly sixty feet in length, weighing up
to one hundred and seventy tons, and on the girth front,
their maximum girth can exceed seventy percent of total length.
So these are big creatures, not as big as the

(46:59):
blue whale by most you know, measuring sticks, but it
is the whale with the most blubber. And we'll get
back to how it's it has a huge head, and
we'll get back to one of what that uh sort
of hump portion of the head is for. Uh, But yeah,
these are These are enormous creatures. Uh. And in terms

(47:20):
of the size rankings, they're generally ranked behind the right
whale right as in right handed or right as incorrect.
The right whale is just a little behind the bowhead
whale and overall size. In fact, they look a lot alike.

(47:40):
The bowhead whale was once known as the greenland right whale. Briefly,
there are three varieties of right whale. The pygmy right
whale is not a true right whale, and the name
right whale is thought to refer to one of two things,
possibly both at the same time. So first of all,
there's English whaling wisdom that right whales were the correct whales,

(48:02):
the right whales to hunt, because they had this trifecta
of features. They were slow, so easy to chase down
and kill, and then when you did kill them, they
were so buoyant from their blubber that they floated. They
definitely floated, so they were easier to harvest. And then
when they were harvested they produced high amounts of oil

(48:24):
and balen per individual. And the oil, of course is key.
We'll get into the balen as well. But in terms
of the bowhead whale, and the right whale species, they
have a lot of blubber, and therefore they produced a
lot of whale oil. Because whale oil was made from
rendered blubber. This was the product of whaling that was

(48:47):
most important to the whaling industry generally, certainly in its
later industrialized stages. You know, humans have hunted whales for
a very long time, but you know, whale oil was
one of the major products during the most destructive heyday
of human whaling. Now. But the other side of the
coin is that, apparently, according to Carwadine, mid nineteenth century

(49:08):
scientific observations were made that these were the right whales
in that they were true and proper examples of what
a whale should be. Which I have a little harder
time wrapping my head around that one, because I mean
it's like, what is the best whale? I mean, you know,
they're all they're all whales. But I think it comes
down to just sort of like basic body size identifiable

(49:30):
as a whale. It is a bleen whale and so forth.
All right, So coming back to the bowhead whale, Yes,
this is your blubber superstar baileina mistacetis, which means mustached whale.
It sounds like it's going to be something about mysterious
whale or something, but no, it's mustached whale. And this
refers to the bowhead whales bleen plates. We talked about

(49:52):
baileen plates previously in our episode on gray whales. These are,
of course the big filtery teeth like structures in the
mouth that home through plankton or the marine animals that
they are consuming. And for the bowhead whale, these are
the longest of any animal, up to four meters or
even five point two meters, so we're talking thirteen to

(50:13):
seventeen feet long these baleen plates individually, and they're you know,
hundreds of them in their mouths. And the name bowhead
stems from their large, strongly arched or bow shaped rostrum
and mouthline.

Speaker 3 (50:26):
Okay, for a second, I thought that was what I
was talking about earlier, but the rosterum and the mouth
line would be different.

Speaker 2 (50:31):
Yeah, this's more below and moving towards the front. What
you're talking about is on the top of the head,
and it's going to come into play here in just
a minute. Okay, So the key to the bowhead's massive
blubber reserves here is that it is an Arctic specialist.
It more than anything lives up to that Melville line,

(50:51):
immersed to his lips for life in those Arctic waters
because it lives exclusively in the Arctic and Subarctic, and
it is the only baileen whale to do so. It
ventures up into the high Arctic during the summer again
like all like other baileen whales, it moves north, chasing

(51:12):
those blooms and the richness of food that it can
that it can achieve up there. But these guys go
really far north and then during the winter they go
back into the lower and Subarctic, but are thought to
stay close to the ice edge. So for whales of
this species venturing down into the Bearing Sea, that's snowbird behavior.

(51:33):
That's like pretty much as southern as they go. They're
definitely not going down to Mexico.

Speaker 3 (51:40):
Nice tropical vacation in Alaska, off the coast of Alaska.

Speaker 2 (51:44):
Yeah, so I mean this. I think this is the
most important thing to keep in mind about about them
and about the role of blubber in their lives is
that they they are extremists. They live in the cold
waters all the time and have are always in close
proximity to sea ice, so they have to have that insulation,
and they have to have more insulation than any of

(52:06):
the other whales in the sea. Now, like other whales,
their main predator outside of human whalers, of course, is
the orca. And according to Carwodine, the bowhead whale's close
association with sea ice maybe how it primarily protects itself
from killer whales that tend to avoid extensive Arctic sea ice.
The problem, of course is that due to climate change,

(52:28):
there is less and less sea ice out there to
protect them. So it's you know, kind of an open
question of how they will adapt and how they are
adapting to these changes. Now, coming back to what you
noted earlier about the shape, the upper shape of the
bowhead's enormous head. It lives in close proximity to sea ice,

(52:49):
and it will venture under sea ice when it's feeding,
and it can stay down for an extended period of
time depending on what it's doing and what the circumstances are. Well,
as with other whales, it's like if they were observed
while being chased by whalers, like, they can stay down
even longer. But bowhead whales will come up under the

(53:13):
ice and they can break through ice that is up
to sixty centimeters almost two feet thick. Whoa yeah, in
order to create their own breathing holes in the ice
large enough for that raised hump like part of their
enormous head to come out and allow their their blowhole
to gain access to the air.

Speaker 3 (53:33):
It's hard to imagine that's true. They can break through
two feet thick of ice, Yeah, sixty unbel but that
would make more sense to me if if it is
true that they can take refuge from their only potential
predators by venturing further, you know, staying around the ice
and venturing further under the ice than their predator is
willing to go.

Speaker 2 (53:53):
Yeah yeah, and also further under the ice than their
competitors willing to go. There are other, of course, far
northern aquatic mammals. You know, we've talked about nar walls before,
but the bowhead whales are pretty exceptional here.

Speaker 4 (54:09):
Now.

Speaker 2 (54:09):
The blubber, of course, provides them that thermal insulation we've
been talking about physical predection, protection against environmental hazards certainly
as well as those energy stores. How much blubber do
they have? Well, as we noted earlier, your sources are
going to vary depending on how they're measuring the blubber,
and it's also going to depend on where on the

(54:30):
body you're looking at. Carbadine says five point five to
twenty eight centimeters or roughly two inches to eleven inches
in thickness, so up to nearly a foot of thickness
in general, So again the thickest of any whale, depending
on how you're measuring it. The bowhead whale is still
going to be at the top of any list.

Speaker 3 (54:51):
In one sense, I'm thinking, man, I would love to
see a cross section of that. But then on the
other hand, of like, oh, that's a little too real,
I guess because of the familiarity with the whaling contact
with it, you know, they really would be cut up
like that. But yeah, seeing a cross section of that
tissue I'm sure is amazing.

Speaker 2 (55:07):
Yeah. Yeah, because again they were heavily targeted by whalers
because like the right whales, they're also slow, deliberate swimmers.
We talked in the in previous episodes about whales how
you basically different to Different whales have different ways of
dealing with the threat of orcas, and it generally comes
down to, like, are you going to try to outrun

(55:27):
it or are you going to fight it off? And
the bowhead whales are not going to outrun the orcas,
and they will turn and fight if needed. But again
it also seems like refuge in the sea ice is
also part of their strategy. But since they are slow,
deliberate swimmers, that's one of the reasons that humans thought

(55:47):
that they were ideal whales for hunting. You know. Sadly
this is as with you know, like other whale species,
like the gray whales. It's it's written that they are
rather cureious about humans. That they encounter humans and boats
and so forth, you know, they'll come up and take
a look, which you know, makes it even all the

(56:09):
more tragic that we were so brutal towards them. Again
during this highly industrial period of human whaling, when they
were you know, intensely hunted and threatened, and as human
whalers took advantage of that slow speed, their rich balen
and their blubber and the latter of which of course
also made them so buoyant. So all these things made

(56:32):
them ideal prey for whaling enterprises.

Speaker 3 (56:35):
But also such an amazing example of what Melville talks
about the you know, the the rare virtue of the
strong individual vitality, the thick walls, and the virtue of
interior spaciousness that takes his weather with him where he
goes and is immersed to his lips for life in
those Arctic waters.

Speaker 2 (56:55):
Joe, you mentioned your desire to see a cross section
of the bowhead whale. Quick image search revealed several very
interesting looking cross sections illustrations of course, so I would
encourage folks to look those up in general, Like the
inside of a whale is always fascinating because you know,
their bone structure is so unique and alien but also familiar.

(57:20):
You know, we can't help but imagine if we ourselves
embarked on some on such an evolutionary journey of the body.
And just also the scale that they're on. Anytime there's
there's a reminder of just like how big is a
human compared to you know, the guts of a particularly
large whale. It's just it's mind Rand.

Speaker 3 (57:40):
Well, Rob, are you excited to talk about blubber for
at least one more episode?

Speaker 2 (57:44):
Absolutely? Yeah, yeah, we we we barely scratch the surface
of the blubber when it comes to human uses for it.
I don't you know. We may come back to whale oil,
but there's so many other uses for certainly the colon
uses I think we're going to be very interesting to
get into, which tend to be tied to older whaling traditions,

(58:06):
that we're more in balance with the creature's natural patterns. Yeah,
but as we said, certainly right in if you have
any Glover thoughts right now, and maybe they will, there'll
be something that we'll read in the next episode or
at least in a later listener mail episode. Just a
reminder to everyone out there that's Stuff to Blow Your
Mind is primarily a science and culture podcast, with core
episodes on Tuesdays and Thursdays, short form episodes on Wednesdays

(58:29):
and on Fridays. We just set aside most serious concerns
to talk about a weird film on Weird House Cinema.

Speaker 3 (58:34):
Huge thanks as always to our excellent audio producer JJ Posway.
If you would like to get in touch with us
with feedback on this episode or any other, to suggest
a topic for the future, or just to say hello,
you can email us at contact at stuff to Blow
your Mind dot com.

Speaker 1 (58:55):
Stuff to Blow Your Mind is production of iHeartRadio. For
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