March 9, 2023 • 45 mins
In this episode of Stuff to Blow Your Mind, Robert and Joe discuss the enigmatic gray whale, noted today for its vast oceanic migrations and curiosity, but known as “devilfish” for its ferocity by the American whalers who hunted it in the past. (part 3 of 3)
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Speaker 1 (00:02):
Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Hey you welcome to Stuff to Blow Your Mind. My
name is Robert Lamb and I'm Joe McCormick, and we're
back with Part three, the final part in our series
on gray whales. Now in the previous episodes, which if
(00:26):
you haven't listened to yet, you'd probably go back and
check out parts one and two. First, in the previous ones,
we described the morphology and behavior of the species scientific
name is Shrichtius robust us. There the robust buddies, the
gray whales, and we talked about their relationship with the
barnacles that often pile up on them like a like
(00:47):
a big old nasty crust. And we talked about their
relationship with their main predator other than humans, the orca.
And today we're going to kick off addressing their amazing
migratory habits, which is probably one of the main things
to understand about this species. Yeah, yeah, And to sort
of draw back to those previous episodes that reiterate that
(01:09):
I did get the chance to see gray whales in
the wild at their breeding lagoons, A particular one of
their breeding lagoons called Ojo Delia Gray Lagoon on the
Baja Peninsula about halfway down the Baja Peninsula, and it
was an amazing experience. So I'll refer back to to
some of my observations alongside the various sided materials that
(01:32):
we're going to be referring to now speaking of those
breeding lagoons. In the last episode, you know, we mostly
discussed these as the safe waters for the birth of
the whale calves and a reason for migration in gray
whales in particular. But as highlighted in one of the
books that I was using here, whales their biology and
behavior by Hammond at all, there are other considerations to
(01:56):
take into account concerning, first of all, just migration of
bailing whales in general. So on the reproductive front, yes,
protection from orcas does seem to be a major factor,
particularly with gray whales, and there's the additional hypothesis that
the whale calves to survive and grow better in warmer waters.
It's also argued that it's simply energetically more efficient to
(02:19):
swim to warmer waters than to overwinter up north. There's
also more visibility and shelter in tropical waters. We talked,
and this comes back to orcas survival to a large extent,
we discussed the gray whales ability to seek shallower waters,
and part of that is that there it sounds like
they're just more nooks and crannies that the whales may
(02:42):
venture into to find refuge. Yeah. So, for example, when
gray whales are threatened by orcas, it's been observed that
they might try to seek shelters, say in kelp beds,
or like in hiding in seaweed, or even in breaking surf,
which apparently helps obscure their presence. Yeah, and we'll come
back to some more details about this in a minute.
(03:04):
The authors here do stress, however, that there's just there's
no one size fits all explanation, especially considering that there
are various differences in behavior among the baling whales in general.
For instance, they mentioned that one factor for many baling whales,
again not gray whales specifically, but but other filter feeding whales,
seems to be that during the summer you have a
(03:26):
stratification of the water column to include a highly photic zone,
resulting in rapid photosynthesis and reproduction of phytoplankton. Phytoplankton are
the plant plankton, and these phytoplankton in turn feed the zooplankton,
which of course are the animal plankton, and this generally
(03:49):
fattens up the entire ecosystem in these waters. But then
in the winter, cooling temps and strong winds break up
the stratification, mixing the vertical water column. Phytoplankton can't stay
near the surfaces easily, there's increasingly less sunlight and prey
availability takes a dive as well. Okay, so the plankton
scene kind of dries up a little bit. Yeah. Now,
(04:12):
as we mentioned, and I believe the first episode, gray
whales are of course rather different than a lot of
the other baling whales, I mean, all the other extent
baling whales, because they're not really going after things like
kelp and zooplankton. No, they're going after those benthic organisms
like isopods in the sand on the sea floor. So
(04:32):
they're not directly feeding for the most part on plankton. However,
the benthic organisms down there are still part of the
food web and are therefore impacted as well by all
of this. Okay, so if you don't recall we described
their typical feeding behavior, I think in part one of
this series where unlike the whales you've probably seen kind
(04:54):
of like zooming around near the surface of the water
and just like letting water wash into their mouths, filtering
out all of the plankton or the krill or whatever
with their billing. The gray whales have a habit of
slamming their heads into the sediment on the ocean bottom
in relatively shallow areas to sort of like scoop up
(05:15):
a bunch of this sediment and then getting like use
their billiing to filter the organisms out of it and
eat those. Yeah, exactly like basically scraping one side of
their face across the seafloor. Now there's another interesting factor
in all this. So we mentioned in one of the
previous episodes that gray whales have been observed in recent
years overwintering in the Arctic and not making the migration
(05:39):
down south in rare instances. And I don't believe we're
talking about reproductive or currently reproducing females in these cases.
But basically this is a situation where we have to
consider climate change. Once again. We have to remember that
climate change has some of its more drastic effects in
the Arctic. And I was reading an interest in OAA
(06:00):
paper dealing with some of this, titled Sentinels of Change
Gray Whales in the Arctic, pointing out that less sea
ice means more exposed ocean areas and this alone has
a huge impact on the environment. But they also point
out the following. So in cold years, what you have
happening first is a spring bloom of plankton. But in
(06:20):
the early spring, most zooplankton are not yet ready to graze. Meanwhile,
the phytoplankton, the plants digging all that sunlight, they're just
going crazy, and there's so much of it that the
zooplankton are in. The zooplankton are not ready to feed
on it yet, so most of it ends up sinking
to the bottom. And what happens at the bottom, well,
(06:42):
that's where the benthic organisms are and they feast on them.
And again that is what the gray whales are primarily
going to eat, those creatures down there that just date
all of this phytoplankton. In warmer years, however, the sea
ice melts too early. There's not enough light to really
power up the spring bloom of phytoplank and so the
phytoplankton bloom is delayed and it doesn't really hit until
(07:05):
of the zooplankton is fully ready to feed, meaning that
the zooplankton can eat most of it, there's less to
rain down to the menthic organisms. Okay, so that sounds
not great for gray whales. That's what it would sound, right, yeah,
because that's their primary feast down there. But what this
particular paper stresses is that as warmer years likely continue
(07:27):
due to climate change, we might see gray whales shift
in their diet. So we mentioned that they're fairly opportunistic,
so they will do some filter feeding in the upper
portions of the water So if they aren't able to
get what they would normally get down there at the bottom,
(07:48):
or it seems like there's more, say zooplankton in the
upper portion of the water column, then they will eat
that and potentially eat that instead. So it's a situation
where they outline that a couple of things happened. We
might to see them displaced from their traditional feeding grounds,
but we also might see a portion of their diet
shift more in favor of filter feeding upwards in the
(08:11):
water column, eating more zooplankton than would normally make up
their diet and I think, goodness. I'm trying to remember
what the percentage was when we talked about it, but
it's like a huge percentage of their known normal diet
is those benthic organisms down there in the sand. So
it's kind of a good news not I don't know
if it's a good news bading situation, but anyway, it
speaks to these organisms have been around for a long time,
(08:34):
and part of their ability to survive has been their
ability to make reasonable adaptations. Yes, and I guess that
brings us back to the issue of the migration, because
what we're talking about right now is primarily what's happening
in their feeding grounds in the Arctic waters. But that's
only half of the story. That's really fatten up up north,
especially when we're talking about this population of the Eastern
(08:56):
Pacific gray whales. The other half of the story is reproduction,
which involves a journey south. That's right, and this is
quite a journey for the gray whales. The distance between
their summer feeding grounds and their winter breeding grounds can
exceed twenty thousand kilometers. That's something like twelve four hundred
and twenty seven miles. Now, it's worth discussing again again
(09:18):
These are not deep ocean whales, and that makes sense
given their diet. They primarily stick to a shallow continental
shelf waters. They stick reasonably close to the coast, and
therefore we see that reflected also in the way they
migrate between these two waters. They're not making a bee
line from one area to the next. Their journey tends
(09:40):
to be more coastal, with some alterations depending on exactly
what their circumstances are. Now, we mentioned that there used
to be a population of North Atlantic gray whales, and
it's thought that they would have fed around Newfoundland, the
Gulf of Saint Lawrence, Iceland, and Europe's North Sea. And
(10:01):
it's thought that they would have found winter breeding refuges
somewhere along the coasts of Georgia and the Carolinas here
in the States, as well as uncertain spots along the
coast of Spain, Portugal, and Morocco. Now, this population was
essentially extinct by the late seventeenth and early eighteenth centuries
do at the very least in large part to whaling,
(10:23):
if not largely to whaling or entirely to whaling. Interestingly enough,
there have been proposals to try and reintroduce North Pacific
gray whales into this region to restore the population. I
think we mentioned this previously. And there's also the possibility
that they may recolonize the area themselves as in the
future as sea ice melts and opens up these waters
(10:43):
to them once again. So the North Pacific population potentially
recolonizing the North Atlantic, but that's kind of hypothetical. We're
not sure exactly how that would pan out, though, I
guess it's always possible, because occasionally you do find whales
like way outside of their their normal ranges, right, They
(11:04):
just kind of pop up in strange places that that
you don't usually find them. Yeah, there are a couple
of outstanding examples of that. Did Carboning points out a
single gray whale was sighted off the coast of Israel
in twenty ten, and in twenty thirteen one was seen
off the coast of Namibia, and it's uncertain exactly why
in both of these cases. Hammond at all point out
that their origin was was almost certainly the North Pacific
(11:26):
population in both cases though, Yeah, that's great. How would
they get that far away? Yeah, I mean, I guess
we know they can swim away as due to their
to their habitual migrations. But yeah, you want to know
the story of that wandering whale. Yeah. Now, now coming
back to that now extinct North Atlantic population. Quick Outlander
(11:48):
note out for everyone out there. I was reminded of this,
My wife reminded maybe that we had watched this. But
the television series adaptation of Outlander has a scene set
on the coast of South Carolina, and again this is
about time travelers going back in time, in which two
of our time traveling characters remark about some whale activity
off the coast and how they wouldn't have seen this
(12:10):
in their original timelines or in the original times and
the footage they use in the show, I had to
check it. It's not gray whales that they're they're using here,
I believe, but it certainly made me think of the
scenario that you're like, Yeah, if you went back in
time before human whaling activity seemingly had a chance to
just drastically alter the ecosystem in the Atlantic, you would
(12:33):
have potentially seen these great whales, Like it would have
been possible for me to see gray whales in my
home state of Georgia, potentially without having to travel to
the other side of the continent and then to another country.
And when is this set an outlander? Is this like
early eighteenth century or something. Yeah, the initial transplant I
(12:55):
think is from nineteen forty five to seventeen forty three. Okay, Yeah,
and certainly, as we'll discuss, given the population changes in
the gray whale at nineteen forty five, it was a
bad time for the gray whale anyway. This also reminded
me of something that our previous guest on the show. This,
I think was while you were out Joe, I talked
(13:16):
with Ryan Tucker Jones, author of the book Read Leviathan,
which is largely about Soviet whaling in the Industrial Age,
but it also discusses just the history of whaling in general,
and it's it's a fascinating look at like why the
Soviet Union got increasingly into whaling during the Industrial Age
(13:37):
and the impact of it, what was also learned scientifically
from it. And there's a there's a bit in that.
This is just from the introduction where he writes, quote,
as someone who grew up in Oregon and California in
the nineteen eighties, I experienced the ocean at the whale's
lowest point, an ocean that had been created by the
Soviet Union as much as anyone. The history of Soviet
(13:58):
whaling belongs to anyone who looks out to the sea
and sees nothing. Oh yeah, it's there. Are a lot
of really haunting moments in the book and just a
lot of great details. Certainly go back and listen to
that interview for more or or just check out the book.
Just a reminder that the gray whale in particular was
hunted near the point of extinction by humans. We slaughtered
(14:18):
them on their migration routes. We slaughtered them in their
northern feeding grounds, and we slaughtered them in their breeding lagoons.
They were afforded full protection in nineteen forty six. Those
Soviet whalers took three hundred and twenty hundred scientific permit
in nineteen sixty, along with another one hundred and thirty
eight illegally. These figures according to Carwadene in Carveding Just
(14:38):
in case you don't remember, I haven't cited him in
this episode, but that's Mark Carwadine's Handbook of Whales, Dolphins
and Porpoises of the World. But adding more context from
Jones here, he notes that by the end of the
classical age of whaling, so the pre industrial sailing age
of whaling, the sort of moby Dick era of whaling. Quote,
humans mainly Americans, had reduced Pacific gray whales from around
(15:00):
twenty four thousand to a remnant population of two thousand.
Atlantic gray whales were entirely extinct, and so from what
I understand today, Atlantic gray whales they are gone for
all we know. And then there are the two populations.
There is the Western Pacific gray whale, which lives along
the eastern coast of the Asian mainland. That population is,
(15:24):
from what we can tell, in pretty rough shape today.
I don't remember how many individuals it's down to, but
it's estimated to be pretty low, whereas the Eastern Pacific
gray whale along the coast of North America is doing okay. Yeah.
And in terms of the classical and industrial whaling, like,
(15:45):
certain species were impacted more in different in different phases.
So the gray whales were slower and they tended to
be closer to shore, so in many respects they were
easier to catch during that classic age of whaling. Though
like we mentioned, they they were the devilfish. They could
certainly put up a hell of a fight as well.
But as the age of industrial whaling brought many of
(16:07):
the faster species like blue whales and fins into the
sort of whaling fold, here those whales had fewer defenses
against whalers. They'd really only ever had to contend with
orca jones rides. But meanwhile, in the age of industrialized
Soviet whaling, quote, gray whales were particularly tricky. Soviet whalers
noted that, despite being slow, the gray was the only
(16:29):
whale and he quotes about which no rules of catching
have been established. Only on rare occasions did gray's move
in a straight line, instead usually swimming in zigzags, making
movements to one or the other side without determined direction.
Science the Soviets hoped might help establish some or other
pattern to its movement. I wonder if the ways that
(16:53):
different whales reacted to threats by human whalers was affected
by the different strategies these species had for dealing with orca. Obviously,
the threats posed by human whalers and orca are going
to be of a very different shape and nature, but
maybe some anti predator strategies aimed at orca were just
(17:14):
also just also happened to buy coincidence be better at
evading human whalers. Yeah, it sounds likely because certainly the end,
one of the things about the industrial ages, you just
had faster ships and they could keep up with with
whales and they could get those whales that were further out.
So gray whales in the North Pacific were greatly reduced
by this time, and those that remained even were even
(17:36):
harder to acquire. Jones also notes that by nineteen thirty six,
the average size of gray whales captured was greatly decreased,
and the reasoning hero was quote the population was no
longer seeing its members to adulthood, because again, these are
creatures that can live I think upwards of late like
eighty years or so if I'm remembering correctly, and they're
just they that's how impacted the population was now today.
(17:59):
Caring notes that while gray whales in general have greatly rebounded,
and like, if you look them up online, you'll quickly
see that they're listed as least concern as far as
conservation status goes, which is which is great news. That's
a heck of a comeback story. But they're still threatened
by oil and gas developments in the Arctic and and
declining sea ice. Other threats include entanglement in fishing gear,
occasional illegal harpooning, chemical pollution, noise pollution, ship collision, and
(18:24):
the expansion of sea salt production in Baja California. In
my own experience down there in Baja California, I mean,
the lagoon that we ventured out too in order to
see the whales was surrounded pretty much only by salt
industry projects, so I can understand where that would be
a concern. Carveding also notes that while the Eastern North
Pacific group is doing great at the moment, there was
(18:46):
you to see some fluctuations. So there was a six
hundred and fifty one whale die off in nineteen ninety
nine through twenty eleven, and that would have been like
a twenty three percent population die off, though this doesn't
necessary daily reflect long term survivability according to the NAA,
and you can have big swings in population like that
(19:07):
and it doesn't necessarily speak to how the species is
doing long term. But that Western North Pacific population, like
we said earlier, this one, according to Carvedin, is quote,
one of the most endangered whale populations in the world.
So even though the species at whole is doing better,
we're mostly looking at the Eastern North Pacific group as
(19:30):
opposed to the Western North Pacific group. Again, to whatever extent,
that's a true separate population because we do see overlap
in their breeding and behavior. So getting more back into
just the migration patterns here that are pretty fascinating. We
(19:53):
have the North Pacific gray whale to contend with here,
and you have these two basic groups. The Eastern North
Pacific grays migrate between those Baja California breeding lagoons and
summer feeding grounds and the bearing chuck Chee and Beaufort seats,
though this range is expanding as the ice opens up again.
The Western North Pacific grays migrate between winter breeding grounds
(20:14):
somewhere in the South China Sea to summer feeding grounds
in the Sea of Okoksk and parts of Kamchatka, and
there is some mixing of these groups in both the
summer and winter. Now, the Eastern North Pacific grays have
the longer of the two migrations, spanning up to fifty
degrees of latitude according to Carwadine, and the shortest return
journey for these whales is about twelve thousand kilometers or
(20:37):
about seven thousand, four hundred and fifty six miles. He
adds that the longest documented migration of any mammal was
a female gray whale with a twenty two thousand, five
hundred and eleven kilometer round trip between sakal And Island,
Russia and Baja California, Mexico. So that would have been
again that we're talking about how there is overlap in
the ranges of the eastern and western. Now note that
(21:01):
there's also apparently a two hundred strong Pacific coast feeding
group that doesn't migrate all the way up to the
Arctic at all, but feeds off a coastal area stretching
between northern California and southeast Alaska. And there's another group
that feeds im Puget Sound. So all right, here are
the stages of the migration, and in covering these stages,
we're going to hit on some of the things we've
(21:22):
discussed already, but try and keep it reasonably. It's the
sink here. But first we'll start with leaving the Arctic. Okay,
they've been feeding. The whales have been feeding up north,
and the signal of the head south seems to be
a combination of the formation of sea ice and the
decreasing day length. Apparently ninety percent leave the bearing sea
through intimac Pass on a sixty day journey to Baja California,
(21:46):
a near term mother's leave first, then other adults, then
immature females, and then immature males. The last are on
their way south while the first group is already on
their way back north. Again. Oh, that's interesting. The orca
threat is far less during this part of the cycle.
Again referring back to the the orcas. The orcas are
(22:06):
are are intelligent and cunning in their hunting of these dangerous, uh,
these fearsome prey species. So at this point, the whales
have been feeding all summer long, so they're they're they're
fueled up, they're they're ready to fight, and their their
calves are are even larger than they were previously. So
(22:27):
everybody's stronger, everyone's well fed. It's not to say the
orcas won't feed or won't attempt to acquire prey, but
this is not the optimal time to do it. And
a reminder of what we talked about last time, uh,
this would be related to the fact that orcas are
going to be mostly trying to prey on newborn whale
(22:47):
calves for their return journey coming up the migratory corridor
back to the feeding grounds, because a healthy adult gray
whale is a pretty hard target, and orcas are observed
to not never, but very rarely try to attack a
healthy adult. Usually what they're trying to do is separate
a young calf and and prey on it. Yeah, exactly.
(23:09):
So they make their way south, and then it's lagoon time,
and there are three main areas that they gather here.
The exact amount of time spent in the lagoon's berries
depending on sex and the presence of calves. Females with
young cows just going to hang out far longer because
you know, they need to bring get that that young
one up to wait up to strength before they head
(23:31):
back out again. Whereas like a male that's come down
to breed, you know, obviously he doesn't have to stay
as long's he can head back up as soon as
he's ready. As we've discussed, these waters provide shelter against
the orca, but they don't provide food. The adult whales
don't feed while they're in the lagoon, and the whales
that are born here while they drink their mother's milk,
(23:51):
and of course that is you know, just going to
sort of drain the mother is even more so this
makes it really important that they fatten up as much
as possible before the journey south exactly. Yeah, like we said,
they seem safe from the orca here because the orca
are hesitant to enter into shallow waters where they won't
be able to employ their full range of pack hunting techniques.
And also where I don't know if we mentioned this either,
(24:13):
but there are a lot of whales in these waters.
Like when I was out there, you'd see just they
were everywhere. There were just hundreds of them. In fact,
I saw they had a tallied count even at the
whale center there and the figures I'm pulling this up
on my phone. I took a picture of it, but
the total count for mothers with babies was three hundred
(24:37):
and twenty two. The lonely whale count was two eighty seven.
So like this is just the count, but it was
like nine hundred and thirty one whales already during that
that breeding season. So another reason I guess to tread carefully.
If you're an orca, you know you're going to go
into this area where you can't use all of your tactics,
and there are tons of whales that, as we mentioned,
(24:59):
may work together against you if you present yourself as
a threat. Right, But that doesn't mean they don't know
about these lagoons, that mean they don't occasionally even venture
in on a scouting mission. They're out there beyond the
limits of the lagoons more or less waiting because again,
as Carveding points out, the orca choose to strike quote
when natural features tip the balance in their favor. All right, So,
(25:21):
but eventually it's time to head north again. These they
haven't been feeding. Everyone needs to get back to those
feeding grounds. So first all the whales except mothers and
calves leave, and they tend to take the more direct
route that has brought them there. So, for instance, if
there's a you know, they stick more or less to
the coast, But if there's an area where there's like
a bay or something, or a little inlet, they're more
(25:44):
likely to just go straight across that inlet instead of
hugging the coast through all the milks and crannies. Right,
a little more as the crow flies, right, But when
the mothers and calves leave. This is about one to
two months later. The calves have grown stronger on and
it's there they're far more prepared than they were to
(26:05):
head out into these dangerous waters. But it ends up
also being a longer trip for them because they are
going to stick closer to the shore. They are going
to travel around all the contours of the shore, you know,
as much as as possible, rather than crossing or cutting corners.
And I think it's pretty obvious why right, Because, as
we discussed last time, one of the main anti predator
strategies of the gray whale trying to get away from
(26:28):
an orca attack or orca harassment is to retreat into
the shallows, where the orcas certainly can't attack effectively and
often won't even try to follow right. So for this reason,
they tend to stick within two hundred meters or about
six hundred and fifty six feet of the shore, often
moving through kelp beds. Now, this is definitely the most
dangerous part of the whole migration cycle, though in general
(26:51):
the return trip, because the calves have had a month
or two to grow and gain strength, but they are
still at their most vulnerable during this leg, so you know,
the mothers that are protecting them have not fed in months,
and then increasingly as they move north, I mean they're
they're also going to grow a little bit weaker. They've
(27:11):
only had the milk to feed off of. And then
again the orca are going to strike wind conditions are
most optimal for them. And generally there are two major
known attack spots along the journey attack hot spots, as
the literature refers to them. One of them is Monterey
Bay in California, and the other is Alaska's Unamaic Pass.
Unamat Pass is the most popular of the two, and
(27:34):
this has to do with the fact that both the
mothers and the calves are kind of at optimal weakness here.
This is further north on the return trip, so like
everything is tipping in favor of the the orca at
this point, and so a number are just going to
be picked off during this period. That's just how it goes,
that's the cycle of predation. But enough are going to
reach those northern waters, and at that point this whole
(27:56):
cycle begins again. They reach the northern waters, it's time
to feed, to gain strength, to fatten up, and the
whole cycle continues and of course, part of this whole
cycle is the barnacles, because the barnacle. Again, those calves
are born without the barnacles, but those barnacles will grow.
The life cycle of the barnacles is tied up with
the life cycle and the travels of these whales. That's right.
(28:19):
We are never without our barnacles, are we, whether metaphorical
or literal. So gray whales, just to do a quick
refresher on our previous discussions about whales and whale barnacles,
gray whales and other species such as humpbacks and so forth,
are regularly found carrying a large load of barnacles. And
a barnacle is a filter feeding crustacean. It's kind of
(28:42):
like a tiny shrimp that is stationary for the adult
portion of its life. So a barnacle will generally swim
around as a larva as a young ling, and it
will find a suitable substrate, then cement its head to
that substrate, and then build a hard shell out of
calcium carbon plates. And these shells can take many different forms.
(29:03):
They can look like anything from a concrete pumpkin to
a little volcano, and then they live by filter feeding.
They wave these little legs called cerri out in the
water to catch bits of plankton and pull them in
and eat them. Some species of barnacle specialize in living
on the bodies of whales, and this is of course
great for the barnacle because it provides a steady flow
(29:26):
of water to feed from. Barnacles. Often, when they're not
on whales, many barnacle species try to find a spot
in the intertidal zone where the tides are going to
be moving waters over them in and out all day,
because they need moving water to help catch their food,
to bring food to them. I think the way we
put it was that they need high foot traffic areas.
(29:47):
So latching onto a whale is a great adaptation. That's
gonna have water flowing over you all the time as
the whale swims. But also it's very helpful in that
it provides protection from predators. And you can see some
evidence of this in the size that whale barnacles grow
to and in the fact that they often have a
shell or plate design that is less defensive looking, like
(30:11):
they close less completely and often have more fleshy bits
just kind of poken out all the time. So this
relationship definitely helps the barnacles. But how does it affect
the whales. That's not entirely clear. We talked about some
arguments several different ways in the previous episode. It may
hurt the whales by causing drag during swimming, would of
(30:32):
course reduce swimming speed and efficiency for the whale. It
might possibly also help the whale in some cases by
providing kind of armor plating for violent encounters with orcas
or interest specific aggression between say male humpbacks during mating season,
but that's not certain. That's a maybe. But whatever the
effect on the whales, it is normal to find gray
(30:54):
whales covered in hundreds of pounds of barnacles by adulthood,
so they've got a bunch of barnacles on there. In fact,
gray whales have a particular specialist type of barnacle that
is unique to them called crypto lapos rakianecte. So that's
the background. But I wanted to come back to barnacles
because I was reading a really interesting article in Hakai
(31:16):
magazine by an author named Mara Gruenbaum. This was published
in November twenty twenty one, and the article is called
what whale barnacles? No very interesting article worth looking up
and reading in full, but I just wanted to mention
a few elements from it that caught my attention. So
one thing I don't think I fully clocked when we
(31:37):
talked about whale barnacles in the previous episode is how
big some of them get. Was some species of whale
barnacles grow very large compared to most barnacles you would
find attached to stationary surfaces. The article here compares them
at the upper end to several things. Compares them to
the size of a coffee mug, a tennis ball, or
(31:58):
a clementine orange. Rob. I don't know how big the
barnacles on the gray whales you saw were, but some
of these photos I've now seen with other objects for
scale makes you realize, like, wow, those are some some beasts. Yeah,
I mean the ones I saw were pretty large, and
then of course you would you would sometimes see them
clump together as well, so that kind of adds to
the feeling. But individually, yeah, some of them are quite large.
(32:31):
So there's one fact that is off handily alluded to
in this article that I hadn't come across before, and
it made me want to do some digging because I
found it fascinating. But there is a passage where Grundbaum
rites quote these unbudging appendages speaking of whale barnacles, of course,
which colonize a dozen odd different whale species, latch on
so tightly that they are practically part of the whale's skin.
(32:55):
As a result, they were carried into caves by Southern
African people who foraged washed up whale meat one hundred
and sixty four thousand years ago. So WHOA, that's an
image prehistoric people foraging whale meat. I don't know why
I wouldn't have imagined that happened before, but it totally
makes sense, so I decided to look up the primary
(33:17):
evidence for this. I believe the author here is citing
some findings from a place called the Pinnacle Point Cave
thirteen b in South Africa, in which fragments of whale
barnacle were found, But this is not, in fact the
only case of whale barnacles being found away from the
ocean in caves inhabited by prehistoric peoples, giving evidence that
(33:40):
these people foraged whale meat. Another example I came across
was a cave in Spain. This was written about in
a paper by Esteban Alvarez Fernandez at All published in
the Quaternary Journal in twenty fourteen. Paper is called occurrence
of Whale barnacles in Nurja Cave, Malaga, Southern Spain Indirect
(34:01):
evidence of whale consumption by humans in the Upper Magdalenian
and the authors write, quote, whale barnacles indicate that maritime
oriented forage or human groups found stranded whales on the
coast and because of the size and weight of the
large bones, transported only certain pieces such as skin, blubber,
and meat to the caves where they were consumed. And
(34:24):
so we have this evidence of consumption of whale flesh
soft parts of whale flesh, not the bones in these
human caves, because the barnacles are in there. How else
would the barnacles get into these human inhabited caves. They're
stuck to whales all the time. So because many whale
barnacles are adapted to a particular host species, you can
also tell in these cases what type of whale meat
(34:47):
the people were eating, and in this case it was
two different species of barnacle that are found on the
southern right whale. That's also interesting because these whales are
only found much farther south today, but the author's right quote.
Because of Antarctic sea ice expansion during the last glacial period,
these whales could have migrated to the northern hemisphere and
(35:09):
reached southern Spain. Oh wow, that's fascinating. So these are
not gray whales. But because gray whales also have associated
barnacle species, you could, by the same method, potentially identify
ancient ranges of gray whales by looking for evidence of
their dedicated barnacles. And there's another way this article gets
(35:29):
into that. You could look at the prehistory of whales
that look at the ancient movements of whales by looking
at barnacles. I'll get to that in the second but
first I wanted to mention a couple of other interesting facts.
So one thing is this article just describes some of
the difficulties in the research on whale barnacles, like it's
hard to acquire whale barnacles alive and study them, say,
(35:52):
to study their reproduction in the lab, for obvious reasons
and for less obvious ones. The obvious reasons would be
like they are attached to living whales, and the less
obvious reasons would be because these barnacles are not as
they're not as hardy from taking them out of their
natural environment because, for example, these whale barnacles typically can't
(36:14):
seal themselves shut completely, so they can't fully close the
door to keep the water inside when you remove them
from their original context. So like you find a whale
washed up on a beach, the whale barnacles on it
will typically die pretty quick, and so no one. The
article stresses how nobody really has figured out yet the
(36:35):
right way to care for and preserve the lives of
these animals once they are taken off of the whale
they belong to. But there's another thing I wanted to emphasize,
grin Bond describes, which is the kind of the more
body horror aspect of the boundary point between whale and barnacle,
which is maybe kind of a gray area, is like
(36:57):
where one begins and the other ends. Grunbaum writes, quote,
each of these barnacles has a shell structure specially evolved
to anchor itself into its host's flesh. Many species have
chambers within their wall plates into which prongs of whale
skin grow upward, strengthening the barnacle's grip. And this further
(37:20):
explains actually like why it is hard to access living
whale barnacles for research. It's not just a question to
kind of like popping one of them off. It would
generally require cutting into the whale's flesh to separate the
barnacle from the whale. Oh yeah, yeah, I mean this,
you know, comes back to like why do the gray
whales have their their signature appearance, And a lot of
(37:42):
it is like part of its the barnacles, but also
like these gray sort of splotches on their body scars
from various things, including scars from where the barnacles were
previously attached. Yeah, yeah, scars, because they're like, you know,
they really like grab a hold they get in there.
Another thing I've read about is that apparently areas underneath
the barnacles tend to become depigmented on whale skin, so
(38:04):
you can often see them by that there'll be like
a different shade than the surrounding skin. Now we're gonna
about to get into a really interesting area here, because
you know, the thing about living your full life on
a migratory large mammal like this is that your life
cycle is intrinsically tied to the movements in life cycle
of your host species, that's right, and partially for this reason,
(38:28):
there's so much we don't know about the whale barnacle
life cycle. There's things we don't know about their cycles
and their reproduction. They're just hard to study. So they
seem to mate with other barnacles nearby on the same whale,
but they wait until the whales go to their coastal
breeding and calving grounds to release their larvae. And these
(38:49):
larvae are probably guided by an attraction to a chemical
signal that helps them find the whale skin. This could
be a chemical emitted by other barnacles already present. So
maybe there's kind of a you know, I don't think
korum sensing is the right word. That's from different but
you know, they sense a congregation of their kind, or
it could be a biosignature from the skin of the
(39:11):
whale itself. Maybe they're attracted to some kind of signature
mammalian molecule. They also have to do some crawling around
on the whale as larvae before they cement themselves down,
because you don't just go anywhere on the whale. There
are favored regions of the whale's body, often the forehead,
the tail, and the forward facing edges of the flippers,
(39:34):
and I think this is because it increases their access
to flowing water and the plankton in it. But finally,
there's a really big interesting thread in this article that's
about studying the chemical composition of whale barnacle shells to
determine where whales travel. So barnacles are there, you know,
(39:55):
their shell builders. They are constantly building up new layers
of their calcium carbonate plates, And at some point researchers
figured out that you could look at the layers of
these plates kind of like tree rings, but by analyzing
the ratio of oxygen isotopes in each layer, you couldn't
just tell, you know, it's not just counting the tree rings.
(40:16):
You could actually say a lot about the properties of
the water in which each layer was formed, So what
was the temperature of the water, what was the salinity, etc.
And actually you could then compare that information to things
we know about different regions of the ocean at different times,
and this would allow you, by proxy to roughly track
(40:41):
the migration history of the whale on which a barnacle
lived by peeling back and analyzing the mini layers of
its plates and Researchers initially studied this on the shells
of living or recently living barnacles, but it turns out
you could even do this with fossilized remains of whale barnacles,
(41:01):
and by this method you can track the movements not
only of living whales or recently living whales, but whales
that lived hundreds of thousands of years ago, and that information,
in turn can help shed light on unsolved problems in
whale evolutions, such as when and why did billeen whales
start migrating groombaumb Wrights quote. One hypothesis suggests that it
(41:25):
happened around three million years ago, when massive ice sheets
started spreading across much of the northern hemisphere. The colder
temperatures would have frozen whales out of some of their
habitats and put more constraints on where plankton could flourish
in Earth's oceans, and the patterns that came to exist
in the locations of these, say food and shelter resources,
(41:48):
would therefore lead to the establishment of migration patterns over time.
We don't know exactly how it happened, but that's one idea,
and so it seems like we can now maybe use
fossilized whale barnacles to get some insight into what those
ancient patterns of migration were when they changed, and what
(42:09):
those what those changes might coincide with is, say, in
the climate sphere. And this of course can help shed
light on things today as well. Doesn't just tell us
about the past, because understanding when and why ancient whales
started changing their migratory patterns, for example, in relationship to
ocean temperatures and sea level and so forth, that could
(42:31):
help us understand what's likely to happen in the near
future with oceans being affected by our rapidly heating planet.
So anyway, it was just a few notes from there,
but that article What Whale Barnacles Know very interesting worth
a read. Yeah, yeah, I mean it's it's interesting to
think about. It's easy to dismiss the barnacles. It's just
this hanger on, just this sex up parasite of the whale,
(42:52):
But there's so much information tied up in the barnacle
about the host species. Well, this has been this has
been a really fun journey. I've really enjoyed getting to
dive in to researching the gray whale. After getting to
have this experience with them. I guess some people would
probably do this in reverse order to do their research
and then have the experience, but for whatever reason, I
(43:12):
end up doing it the other way around most of
the time. But I enjoyed I kind of that's one
way to sort of draw out these experiences. Oh, I
don't think it's a bad way at all, experience and
then reflect. Yeah. Yeah. By the way, I've cited several
authors and sources that were helpful in the research for
these episodes, but I'd also like to throw in some
hefty things to the local guides at the Ojo de
(43:33):
Layabre Lagoon, some of which have been doing this sort
of guide work every year for something like thirty five years,
as well as the international tour guides that I had there,
Keith Hassan and Donna in particular. Everyone was delightful and
full of wonderful facts and observations about the whales, and
I also really enjoyed the company of the folks that
my family toured with. In case any of you out
(43:55):
there having to be listening, the great thing about a
trip like this is that no one is that they
are is just kind of sort of into Wales like everyone,
At least in my experience, everyone was really excited, really
into them, and really compassionate for them. So yeah, just
a shout out if should any of you be listening.
All right, we're gonna go ahead and close the book
(44:16):
on this one, but we'll be back with more episodes
next week. Just a reminder that Stuff to Blow Your
Mind is primarily a science podcast, with core episodes publishing
on Tuesdays and Thursdays, but on Mondays we do listener mail.
On Wednesday's a short form artifact or monster fact episode,
and on Fridays we do Weird House Cinema. That's our
time to set aside most serious concerns and just talk
about a strange film. Huge thanks to our audio producer
(44:38):
JJ Poseway. 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, to share something interesting,
or just to say hello, you can email us at
contact at stuff to Blow your Mind dot com. Stuff
(45:00):
to Blow Your Mind is production of iHeartRadio. For more
podcasts from my heart Radio, it's the iHeartRadio app, Apple Podcasts,
or wherever you're listening to your favorite shows.
Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Hey you welcome to Stuff to Blow Your Mind. My
name is Robert Lamb and I'm Joe McCormick, and we're
back with Part three, the final part in our series
on gray whales. Now in the previous episodes, which if
(00:26):
you haven't listened to yet, you'd probably go back and
check out parts one and two. First, in the previous ones,
we described the morphology and behavior of the species scientific
name is Shrichtius robust us. There the robust buddies, the
gray whales, and we talked about their relationship with the
barnacles that often pile up on them like a like
(00:47):
a big old nasty crust. And we talked about their
relationship with their main predator other than humans, the orca.
And today we're going to kick off addressing their amazing
migratory habits, which is probably one of the main things
to understand about this species. Yeah, yeah, And to sort
of draw back to those previous episodes that reiterate that
(01:09):
I did get the chance to see gray whales in
the wild at their breeding lagoons, A particular one of
their breeding lagoons called Ojo Delia Gray Lagoon on the
Baja Peninsula about halfway down the Baja Peninsula, and it
was an amazing experience. So I'll refer back to to
some of my observations alongside the various sided materials that
(01:32):
we're going to be referring to now speaking of those
breeding lagoons. In the last episode, you know, we mostly
discussed these as the safe waters for the birth of
the whale calves and a reason for migration in gray
whales in particular. But as highlighted in one of the
books that I was using here, whales their biology and
behavior by Hammond at all, there are other considerations to
(01:56):
take into account concerning, first of all, just migration of
bailing whales in general. So on the reproductive front, yes,
protection from orcas does seem to be a major factor,
particularly with gray whales, and there's the additional hypothesis that
the whale calves to survive and grow better in warmer waters.
It's also argued that it's simply energetically more efficient to
(02:19):
swim to warmer waters than to overwinter up north. There's
also more visibility and shelter in tropical waters. We talked,
and this comes back to orcas survival to a large extent,
we discussed the gray whales ability to seek shallower waters,
and part of that is that there it sounds like
they're just more nooks and crannies that the whales may
(02:42):
venture into to find refuge. Yeah. So, for example, when
gray whales are threatened by orcas, it's been observed that
they might try to seek shelters, say in kelp beds,
or like in hiding in seaweed, or even in breaking surf,
which apparently helps obscure their presence. Yeah, and we'll come
back to some more details about this in a minute.
(03:04):
The authors here do stress, however, that there's just there's
no one size fits all explanation, especially considering that there
are various differences in behavior among the baling whales in general.
For instance, they mentioned that one factor for many baling whales,
again not gray whales specifically, but but other filter feeding whales,
seems to be that during the summer you have a
(03:26):
stratification of the water column to include a highly photic zone,
resulting in rapid photosynthesis and reproduction of phytoplankton. Phytoplankton are
the plant plankton, and these phytoplankton in turn feed the zooplankton,
which of course are the animal plankton, and this generally
(03:49):
fattens up the entire ecosystem in these waters. But then
in the winter, cooling temps and strong winds break up
the stratification, mixing the vertical water column. Phytoplankton can't stay
near the surfaces easily, there's increasingly less sunlight and prey
availability takes a dive as well. Okay, so the plankton
scene kind of dries up a little bit. Yeah. Now,
(04:12):
as we mentioned, and I believe the first episode, gray
whales are of course rather different than a lot of
the other baling whales, I mean, all the other extent
baling whales, because they're not really going after things like
kelp and zooplankton. No, they're going after those benthic organisms
like isopods in the sand on the sea floor. So
(04:32):
they're not directly feeding for the most part on plankton. However,
the benthic organisms down there are still part of the
food web and are therefore impacted as well by all
of this. Okay, so if you don't recall we described
their typical feeding behavior, I think in part one of
this series where unlike the whales you've probably seen kind
(04:54):
of like zooming around near the surface of the water
and just like letting water wash into their mouths, filtering
out all of the plankton or the krill or whatever
with their billing. The gray whales have a habit of
slamming their heads into the sediment on the ocean bottom
in relatively shallow areas to sort of like scoop up
(05:15):
a bunch of this sediment and then getting like use
their billiing to filter the organisms out of it and
eat those. Yeah, exactly like basically scraping one side of
their face across the seafloor. Now there's another interesting factor
in all this. So we mentioned in one of the
previous episodes that gray whales have been observed in recent
years overwintering in the Arctic and not making the migration
(05:39):
down south in rare instances. And I don't believe we're
talking about reproductive or currently reproducing females in these cases.
But basically this is a situation where we have to
consider climate change. Once again. We have to remember that
climate change has some of its more drastic effects in
the Arctic. And I was reading an interest in OAA
(06:00):
paper dealing with some of this, titled Sentinels of Change
Gray Whales in the Arctic, pointing out that less sea
ice means more exposed ocean areas and this alone has
a huge impact on the environment. But they also point
out the following. So in cold years, what you have
happening first is a spring bloom of plankton. But in
(06:20):
the early spring, most zooplankton are not yet ready to graze. Meanwhile,
the phytoplankton, the plants digging all that sunlight, they're just
going crazy, and there's so much of it that the
zooplankton are in. The zooplankton are not ready to feed
on it yet, so most of it ends up sinking
to the bottom. And what happens at the bottom, well,
(06:42):
that's where the benthic organisms are and they feast on them.
And again that is what the gray whales are primarily
going to eat, those creatures down there that just date
all of this phytoplankton. In warmer years, however, the sea
ice melts too early. There's not enough light to really
power up the spring bloom of phytoplank and so the
phytoplankton bloom is delayed and it doesn't really hit until
(07:05):
of the zooplankton is fully ready to feed, meaning that
the zooplankton can eat most of it, there's less to
rain down to the menthic organisms. Okay, so that sounds
not great for gray whales. That's what it would sound, right, yeah,
because that's their primary feast down there. But what this
particular paper stresses is that as warmer years likely continue
(07:27):
due to climate change, we might see gray whales shift
in their diet. So we mentioned that they're fairly opportunistic,
so they will do some filter feeding in the upper
portions of the water So if they aren't able to
get what they would normally get down there at the bottom,
(07:48):
or it seems like there's more, say zooplankton in the
upper portion of the water column, then they will eat
that and potentially eat that instead. So it's a situation
where they outline that a couple of things happened. We
might to see them displaced from their traditional feeding grounds,
but we also might see a portion of their diet
shift more in favor of filter feeding upwards in the
(08:11):
water column, eating more zooplankton than would normally make up
their diet and I think, goodness. I'm trying to remember
what the percentage was when we talked about it, but
it's like a huge percentage of their known normal diet
is those benthic organisms down there in the sand. So
it's kind of a good news not I don't know
if it's a good news bading situation, but anyway, it
speaks to these organisms have been around for a long time,
(08:34):
and part of their ability to survive has been their
ability to make reasonable adaptations. Yes, and I guess that
brings us back to the issue of the migration, because
what we're talking about right now is primarily what's happening
in their feeding grounds in the Arctic waters. But that's
only half of the story. That's really fatten up up north,
especially when we're talking about this population of the Eastern
(08:56):
Pacific gray whales. The other half of the story is reproduction,
which involves a journey south. That's right, and this is
quite a journey for the gray whales. The distance between
their summer feeding grounds and their winter breeding grounds can
exceed twenty thousand kilometers. That's something like twelve four hundred
and twenty seven miles. Now, it's worth discussing again again
(09:18):
These are not deep ocean whales, and that makes sense
given their diet. They primarily stick to a shallow continental
shelf waters. They stick reasonably close to the coast, and
therefore we see that reflected also in the way they
migrate between these two waters. They're not making a bee
line from one area to the next. Their journey tends
(09:40):
to be more coastal, with some alterations depending on exactly
what their circumstances are. Now, we mentioned that there used
to be a population of North Atlantic gray whales, and
it's thought that they would have fed around Newfoundland, the
Gulf of Saint Lawrence, Iceland, and Europe's North Sea. And
(10:01):
it's thought that they would have found winter breeding refuges
somewhere along the coasts of Georgia and the Carolinas here
in the States, as well as uncertain spots along the
coast of Spain, Portugal, and Morocco. Now, this population was
essentially extinct by the late seventeenth and early eighteenth centuries
do at the very least in large part to whaling,
(10:23):
if not largely to whaling or entirely to whaling. Interestingly enough,
there have been proposals to try and reintroduce North Pacific
gray whales into this region to restore the population. I
think we mentioned this previously. And there's also the possibility
that they may recolonize the area themselves as in the
future as sea ice melts and opens up these waters
(10:43):
to them once again. So the North Pacific population potentially
recolonizing the North Atlantic, but that's kind of hypothetical. We're
not sure exactly how that would pan out, though, I
guess it's always possible, because occasionally you do find whales
like way outside of their their normal ranges, right, They
(11:04):
just kind of pop up in strange places that that
you don't usually find them. Yeah, there are a couple
of outstanding examples of that. Did Carboning points out a
single gray whale was sighted off the coast of Israel
in twenty ten, and in twenty thirteen one was seen
off the coast of Namibia, and it's uncertain exactly why
in both of these cases. Hammond at all point out
that their origin was was almost certainly the North Pacific
(11:26):
population in both cases though, Yeah, that's great. How would
they get that far away? Yeah, I mean, I guess
we know they can swim away as due to their
to their habitual migrations. But yeah, you want to know
the story of that wandering whale. Yeah. Now, now coming
back to that now extinct North Atlantic population. Quick Outlander
(11:48):
note out for everyone out there. I was reminded of this,
My wife reminded maybe that we had watched this. But
the television series adaptation of Outlander has a scene set
on the coast of South Carolina, and again this is
about time travelers going back in time, in which two
of our time traveling characters remark about some whale activity
off the coast and how they wouldn't have seen this
(12:10):
in their original timelines or in the original times and
the footage they use in the show, I had to
check it. It's not gray whales that they're they're using here,
I believe, but it certainly made me think of the
scenario that you're like, Yeah, if you went back in
time before human whaling activity seemingly had a chance to
just drastically alter the ecosystem in the Atlantic, you would
(12:33):
have potentially seen these great whales, Like it would have
been possible for me to see gray whales in my
home state of Georgia, potentially without having to travel to
the other side of the continent and then to another country.
And when is this set an outlander? Is this like
early eighteenth century or something. Yeah, the initial transplant I
(12:55):
think is from nineteen forty five to seventeen forty three. Okay, Yeah,
and certainly, as we'll discuss, given the population changes in
the gray whale at nineteen forty five, it was a
bad time for the gray whale anyway. This also reminded
me of something that our previous guest on the show. This,
I think was while you were out Joe, I talked
(13:16):
with Ryan Tucker Jones, author of the book Read Leviathan,
which is largely about Soviet whaling in the Industrial Age,
but it also discusses just the history of whaling in general,
and it's it's a fascinating look at like why the
Soviet Union got increasingly into whaling during the Industrial Age
(13:37):
and the impact of it, what was also learned scientifically
from it. And there's a there's a bit in that.
This is just from the introduction where he writes, quote,
as someone who grew up in Oregon and California in
the nineteen eighties, I experienced the ocean at the whale's
lowest point, an ocean that had been created by the
Soviet Union as much as anyone. The history of Soviet
(13:58):
whaling belongs to anyone who looks out to the sea
and sees nothing. Oh yeah, it's there. Are a lot
of really haunting moments in the book and just a
lot of great details. Certainly go back and listen to
that interview for more or or just check out the book.
Just a reminder that the gray whale in particular was
hunted near the point of extinction by humans. We slaughtered
(14:18):
them on their migration routes. We slaughtered them in their
northern feeding grounds, and we slaughtered them in their breeding lagoons.
They were afforded full protection in nineteen forty six. Those
Soviet whalers took three hundred and twenty hundred scientific permit
in nineteen sixty, along with another one hundred and thirty
eight illegally. These figures according to Carwadene in Carveding Just
(14:38):
in case you don't remember, I haven't cited him in
this episode, but that's Mark Carwadine's Handbook of Whales, Dolphins
and Porpoises of the World. But adding more context from
Jones here, he notes that by the end of the
classical age of whaling, so the pre industrial sailing age
of whaling, the sort of moby Dick era of whaling. Quote,
humans mainly Americans, had reduced Pacific gray whales from around
(15:00):
twenty four thousand to a remnant population of two thousand.
Atlantic gray whales were entirely extinct, and so from what
I understand today, Atlantic gray whales they are gone for
all we know. And then there are the two populations.
There is the Western Pacific gray whale, which lives along
the eastern coast of the Asian mainland. That population is,
(15:24):
from what we can tell, in pretty rough shape today.
I don't remember how many individuals it's down to, but
it's estimated to be pretty low, whereas the Eastern Pacific
gray whale along the coast of North America is doing okay. Yeah.
And in terms of the classical and industrial whaling, like,
(15:45):
certain species were impacted more in different in different phases.
So the gray whales were slower and they tended to
be closer to shore, so in many respects they were
easier to catch during that classic age of whaling. Though
like we mentioned, they they were the devilfish. They could
certainly put up a hell of a fight as well.
But as the age of industrial whaling brought many of
(16:07):
the faster species like blue whales and fins into the
sort of whaling fold, here those whales had fewer defenses
against whalers. They'd really only ever had to contend with
orca jones rides. But meanwhile, in the age of industrialized
Soviet whaling, quote, gray whales were particularly tricky. Soviet whalers
noted that, despite being slow, the gray was the only
(16:29):
whale and he quotes about which no rules of catching
have been established. Only on rare occasions did gray's move
in a straight line, instead usually swimming in zigzags, making
movements to one or the other side without determined direction.
Science the Soviets hoped might help establish some or other
pattern to its movement. I wonder if the ways that
(16:53):
different whales reacted to threats by human whalers was affected
by the different strategies these species had for dealing with orca. Obviously,
the threats posed by human whalers and orca are going
to be of a very different shape and nature, but
maybe some anti predator strategies aimed at orca were just
(17:14):
also just also happened to buy coincidence be better at
evading human whalers. Yeah, it sounds likely because certainly the end,
one of the things about the industrial ages, you just
had faster ships and they could keep up with with
whales and they could get those whales that were further out.
So gray whales in the North Pacific were greatly reduced
by this time, and those that remained even were even
(17:36):
harder to acquire. Jones also notes that by nineteen thirty six,
the average size of gray whales captured was greatly decreased,
and the reasoning hero was quote the population was no
longer seeing its members to adulthood, because again, these are
creatures that can live I think upwards of late like
eighty years or so if I'm remembering correctly, and they're
just they that's how impacted the population was now today.
(17:59):
Caring notes that while gray whales in general have greatly rebounded,
and like, if you look them up online, you'll quickly
see that they're listed as least concern as far as
conservation status goes, which is which is great news. That's
a heck of a comeback story. But they're still threatened
by oil and gas developments in the Arctic and and
declining sea ice. Other threats include entanglement in fishing gear,
occasional illegal harpooning, chemical pollution, noise pollution, ship collision, and
(18:24):
the expansion of sea salt production in Baja California. In
my own experience down there in Baja California, I mean,
the lagoon that we ventured out too in order to
see the whales was surrounded pretty much only by salt
industry projects, so I can understand where that would be
a concern. Carveding also notes that while the Eastern North
Pacific group is doing great at the moment, there was
(18:46):
you to see some fluctuations. So there was a six
hundred and fifty one whale die off in nineteen ninety
nine through twenty eleven, and that would have been like
a twenty three percent population die off, though this doesn't
necessary daily reflect long term survivability according to the NAA,
and you can have big swings in population like that
(19:07):
and it doesn't necessarily speak to how the species is
doing long term. But that Western North Pacific population, like
we said earlier, this one, according to Carvedin, is quote,
one of the most endangered whale populations in the world.
So even though the species at whole is doing better,
we're mostly looking at the Eastern North Pacific group as
(19:30):
opposed to the Western North Pacific group. Again, to whatever extent,
that's a true separate population because we do see overlap
in their breeding and behavior. So getting more back into
just the migration patterns here that are pretty fascinating. We
(19:53):
have the North Pacific gray whale to contend with here,
and you have these two basic groups. The Eastern North
Pacific grays migrate between those Baja California breeding lagoons and
summer feeding grounds and the bearing chuck Chee and Beaufort seats,
though this range is expanding as the ice opens up again.
The Western North Pacific grays migrate between winter breeding grounds
(20:14):
somewhere in the South China Sea to summer feeding grounds
in the Sea of Okoksk and parts of Kamchatka, and
there is some mixing of these groups in both the
summer and winter. Now, the Eastern North Pacific grays have
the longer of the two migrations, spanning up to fifty
degrees of latitude according to Carwadine, and the shortest return
journey for these whales is about twelve thousand kilometers or
(20:37):
about seven thousand, four hundred and fifty six miles. He
adds that the longest documented migration of any mammal was
a female gray whale with a twenty two thousand, five
hundred and eleven kilometer round trip between sakal And Island,
Russia and Baja California, Mexico. So that would have been
again that we're talking about how there is overlap in
the ranges of the eastern and western. Now note that
(21:01):
there's also apparently a two hundred strong Pacific coast feeding
group that doesn't migrate all the way up to the
Arctic at all, but feeds off a coastal area stretching
between northern California and southeast Alaska. And there's another group
that feeds im Puget Sound. So all right, here are
the stages of the migration, and in covering these stages,
we're going to hit on some of the things we've
(21:22):
discussed already, but try and keep it reasonably. It's the
sink here. But first we'll start with leaving the Arctic. Okay,
they've been feeding. The whales have been feeding up north,
and the signal of the head south seems to be
a combination of the formation of sea ice and the
decreasing day length. Apparently ninety percent leave the bearing sea
through intimac Pass on a sixty day journey to Baja California,
(21:46):
a near term mother's leave first, then other adults, then
immature females, and then immature males. The last are on
their way south while the first group is already on
their way back north. Again. Oh, that's interesting. The orca
threat is far less during this part of the cycle.
Again referring back to the the orcas. The orcas are
(22:06):
are are intelligent and cunning in their hunting of these dangerous, uh,
these fearsome prey species. So at this point, the whales
have been feeding all summer long, so they're they're they're
fueled up, they're they're ready to fight, and their their
calves are are even larger than they were previously. So
(22:27):
everybody's stronger, everyone's well fed. It's not to say the
orcas won't feed or won't attempt to acquire prey, but
this is not the optimal time to do it. And
a reminder of what we talked about last time, uh,
this would be related to the fact that orcas are
going to be mostly trying to prey on newborn whale
(22:47):
calves for their return journey coming up the migratory corridor
back to the feeding grounds, because a healthy adult gray
whale is a pretty hard target, and orcas are observed
to not never, but very rarely try to attack a
healthy adult. Usually what they're trying to do is separate
a young calf and and prey on it. Yeah, exactly.
(23:09):
So they make their way south, and then it's lagoon time,
and there are three main areas that they gather here.
The exact amount of time spent in the lagoon's berries
depending on sex and the presence of calves. Females with
young cows just going to hang out far longer because
you know, they need to bring get that that young
one up to wait up to strength before they head
(23:31):
back out again. Whereas like a male that's come down
to breed, you know, obviously he doesn't have to stay
as long's he can head back up as soon as
he's ready. As we've discussed, these waters provide shelter against
the orca, but they don't provide food. The adult whales
don't feed while they're in the lagoon, and the whales
that are born here while they drink their mother's milk,
(23:51):
and of course that is you know, just going to
sort of drain the mother is even more so this
makes it really important that they fatten up as much
as possible before the journey south exactly. Yeah, like we said,
they seem safe from the orca here because the orca
are hesitant to enter into shallow waters where they won't
be able to employ their full range of pack hunting techniques.
And also where I don't know if we mentioned this either,
(24:13):
but there are a lot of whales in these waters.
Like when I was out there, you'd see just they
were everywhere. There were just hundreds of them. In fact,
I saw they had a tallied count even at the
whale center there and the figures I'm pulling this up
on my phone. I took a picture of it, but
the total count for mothers with babies was three hundred
(24:37):
and twenty two. The lonely whale count was two eighty seven.
So like this is just the count, but it was
like nine hundred and thirty one whales already during that
that breeding season. So another reason I guess to tread carefully.
If you're an orca, you know you're going to go
into this area where you can't use all of your tactics,
and there are tons of whales that, as we mentioned,
(24:59):
may work together against you if you present yourself as
a threat. Right, But that doesn't mean they don't know
about these lagoons, that mean they don't occasionally even venture
in on a scouting mission. They're out there beyond the
limits of the lagoons more or less waiting because again,
as Carveding points out, the orca choose to strike quote
when natural features tip the balance in their favor. All right, So,
(25:21):
but eventually it's time to head north again. These they
haven't been feeding. Everyone needs to get back to those
feeding grounds. So first all the whales except mothers and
calves leave, and they tend to take the more direct
route that has brought them there. So, for instance, if
there's a you know, they stick more or less to
the coast, But if there's an area where there's like
a bay or something, or a little inlet, they're more
(25:44):
likely to just go straight across that inlet instead of
hugging the coast through all the milks and crannies. Right,
a little more as the crow flies, right, But when
the mothers and calves leave. This is about one to
two months later. The calves have grown stronger on and
it's there they're far more prepared than they were to
(26:05):
head out into these dangerous waters. But it ends up
also being a longer trip for them because they are
going to stick closer to the shore. They are going
to travel around all the contours of the shore, you know,
as much as as possible, rather than crossing or cutting corners.
And I think it's pretty obvious why right, Because, as
we discussed last time, one of the main anti predator
strategies of the gray whale trying to get away from
(26:28):
an orca attack or orca harassment is to retreat into
the shallows, where the orcas certainly can't attack effectively and
often won't even try to follow right. So for this reason,
they tend to stick within two hundred meters or about
six hundred and fifty six feet of the shore, often
moving through kelp beds. Now, this is definitely the most
dangerous part of the whole migration cycle, though in general
(26:51):
the return trip, because the calves have had a month
or two to grow and gain strength, but they are
still at their most vulnerable during this leg, so you know,
the mothers that are protecting them have not fed in months,
and then increasingly as they move north, I mean they're
they're also going to grow a little bit weaker. They've
(27:11):
only had the milk to feed off of. And then
again the orca are going to strike wind conditions are
most optimal for them. And generally there are two major
known attack spots along the journey attack hot spots, as
the literature refers to them. One of them is Monterey
Bay in California, and the other is Alaska's Unamaic Pass.
Unamat Pass is the most popular of the two, and
(27:34):
this has to do with the fact that both the
mothers and the calves are kind of at optimal weakness here.
This is further north on the return trip, so like
everything is tipping in favor of the the orca at
this point, and so a number are just going to
be picked off during this period. That's just how it goes,
that's the cycle of predation. But enough are going to
reach those northern waters, and at that point this whole
(27:56):
cycle begins again. They reach the northern waters, it's time
to feed, to gain strength, to fatten up, and the
whole cycle continues and of course, part of this whole
cycle is the barnacles, because the barnacle. Again, those calves
are born without the barnacles, but those barnacles will grow.
The life cycle of the barnacles is tied up with
the life cycle and the travels of these whales. That's right.
(28:19):
We are never without our barnacles, are we, whether metaphorical
or literal. So gray whales, just to do a quick
refresher on our previous discussions about whales and whale barnacles,
gray whales and other species such as humpbacks and so forth,
are regularly found carrying a large load of barnacles. And
a barnacle is a filter feeding crustacean. It's kind of
(28:42):
like a tiny shrimp that is stationary for the adult
portion of its life. So a barnacle will generally swim
around as a larva as a young ling, and it
will find a suitable substrate, then cement its head to
that substrate, and then build a hard shell out of
calcium carbon plates. And these shells can take many different forms.
(29:03):
They can look like anything from a concrete pumpkin to
a little volcano, and then they live by filter feeding.
They wave these little legs called cerri out in the
water to catch bits of plankton and pull them in
and eat them. Some species of barnacle specialize in living
on the bodies of whales, and this is of course
great for the barnacle because it provides a steady flow
(29:26):
of water to feed from. Barnacles. Often, when they're not
on whales, many barnacle species try to find a spot
in the intertidal zone where the tides are going to
be moving waters over them in and out all day,
because they need moving water to help catch their food,
to bring food to them. I think the way we
put it was that they need high foot traffic areas.
(29:47):
So latching onto a whale is a great adaptation. That's
gonna have water flowing over you all the time as
the whale swims. But also it's very helpful in that
it provides protection from predators. And you can see some
evidence of this in the size that whale barnacles grow
to and in the fact that they often have a
shell or plate design that is less defensive looking, like
(30:11):
they close less completely and often have more fleshy bits
just kind of poken out all the time. So this
relationship definitely helps the barnacles. But how does it affect
the whales. That's not entirely clear. We talked about some
arguments several different ways in the previous episode. It may
hurt the whales by causing drag during swimming, would of
(30:32):
course reduce swimming speed and efficiency for the whale. It
might possibly also help the whale in some cases by
providing kind of armor plating for violent encounters with orcas
or interest specific aggression between say male humpbacks during mating season,
but that's not certain. That's a maybe. But whatever the
effect on the whales, it is normal to find gray
(30:54):
whales covered in hundreds of pounds of barnacles by adulthood,
so they've got a bunch of barnacles on there. In fact,
gray whales have a particular specialist type of barnacle that
is unique to them called crypto lapos rakianecte. So that's
the background. But I wanted to come back to barnacles
because I was reading a really interesting article in Hakai
(31:16):
magazine by an author named Mara Gruenbaum. This was published
in November twenty twenty one, and the article is called
what whale barnacles? No very interesting article worth looking up
and reading in full, but I just wanted to mention
a few elements from it that caught my attention. So
one thing I don't think I fully clocked when we
(31:37):
talked about whale barnacles in the previous episode is how
big some of them get. Was some species of whale
barnacles grow very large compared to most barnacles you would
find attached to stationary surfaces. The article here compares them
at the upper end to several things. Compares them to
the size of a coffee mug, a tennis ball, or
(31:58):
a clementine orange. Rob. I don't know how big the
barnacles on the gray whales you saw were, but some
of these photos I've now seen with other objects for
scale makes you realize, like, wow, those are some some beasts. Yeah,
I mean the ones I saw were pretty large, and
then of course you would you would sometimes see them
clump together as well, so that kind of adds to
the feeling. But individually, yeah, some of them are quite large.
(32:31):
So there's one fact that is off handily alluded to
in this article that I hadn't come across before, and
it made me want to do some digging because I
found it fascinating. But there is a passage where Grundbaum
rites quote these unbudging appendages speaking of whale barnacles, of course,
which colonize a dozen odd different whale species, latch on
so tightly that they are practically part of the whale's skin.
(32:55):
As a result, they were carried into caves by Southern
African people who foraged washed up whale meat one hundred
and sixty four thousand years ago. So WHOA, that's an
image prehistoric people foraging whale meat. I don't know why
I wouldn't have imagined that happened before, but it totally
makes sense, so I decided to look up the primary
(33:17):
evidence for this. I believe the author here is citing
some findings from a place called the Pinnacle Point Cave
thirteen b in South Africa, in which fragments of whale
barnacle were found, But this is not, in fact the
only case of whale barnacles being found away from the
ocean in caves inhabited by prehistoric peoples, giving evidence that
(33:40):
these people foraged whale meat. Another example I came across
was a cave in Spain. This was written about in
a paper by Esteban Alvarez Fernandez at All published in
the Quaternary Journal in twenty fourteen. Paper is called occurrence
of Whale barnacles in Nurja Cave, Malaga, Southern Spain Indirect
(34:01):
evidence of whale consumption by humans in the Upper Magdalenian
and the authors write, quote, whale barnacles indicate that maritime
oriented forage or human groups found stranded whales on the
coast and because of the size and weight of the
large bones, transported only certain pieces such as skin, blubber,
and meat to the caves where they were consumed. And
(34:24):
so we have this evidence of consumption of whale flesh
soft parts of whale flesh, not the bones in these
human caves, because the barnacles are in there. How else
would the barnacles get into these human inhabited caves. They're
stuck to whales all the time. So because many whale
barnacles are adapted to a particular host species, you can
also tell in these cases what type of whale meat
(34:47):
the people were eating, and in this case it was
two different species of barnacle that are found on the
southern right whale. That's also interesting because these whales are
only found much farther south today, but the author's right quote.
Because of Antarctic sea ice expansion during the last glacial period,
these whales could have migrated to the northern hemisphere and
(35:09):
reached southern Spain. Oh wow, that's fascinating. So these are
not gray whales. But because gray whales also have associated
barnacle species, you could, by the same method, potentially identify
ancient ranges of gray whales by looking for evidence of
their dedicated barnacles. And there's another way this article gets
(35:29):
into that. You could look at the prehistory of whales
that look at the ancient movements of whales by looking
at barnacles. I'll get to that in the second but
first I wanted to mention a couple of other interesting facts.
So one thing is this article just describes some of
the difficulties in the research on whale barnacles, like it's
hard to acquire whale barnacles alive and study them, say,
(35:52):
to study their reproduction in the lab, for obvious reasons
and for less obvious ones. The obvious reasons would be
like they are attached to living whales, and the less
obvious reasons would be because these barnacles are not as
they're not as hardy from taking them out of their
natural environment because, for example, these whale barnacles typically can't
(36:14):
seal themselves shut completely, so they can't fully close the
door to keep the water inside when you remove them
from their original context. So like you find a whale
washed up on a beach, the whale barnacles on it
will typically die pretty quick, and so no one. The
article stresses how nobody really has figured out yet the
(36:35):
right way to care for and preserve the lives of
these animals once they are taken off of the whale
they belong to. But there's another thing I wanted to emphasize,
grin Bond describes, which is the kind of the more
body horror aspect of the boundary point between whale and barnacle,
which is maybe kind of a gray area, is like
(36:57):
where one begins and the other ends. Grunbaum writes, quote,
each of these barnacles has a shell structure specially evolved
to anchor itself into its host's flesh. Many species have
chambers within their wall plates into which prongs of whale
skin grow upward, strengthening the barnacle's grip. And this further
(37:20):
explains actually like why it is hard to access living
whale barnacles for research. It's not just a question to
kind of like popping one of them off. It would
generally require cutting into the whale's flesh to separate the
barnacle from the whale. Oh yeah, yeah, I mean this,
you know, comes back to like why do the gray
whales have their their signature appearance, And a lot of
(37:42):
it is like part of its the barnacles, but also
like these gray sort of splotches on their body scars
from various things, including scars from where the barnacles were
previously attached. Yeah, yeah, scars, because they're like, you know,
they really like grab a hold they get in there.
Another thing I've read about is that apparently areas underneath
the barnacles tend to become depigmented on whale skin, so
(38:04):
you can often see them by that there'll be like
a different shade than the surrounding skin. Now we're gonna
about to get into a really interesting area here, because
you know, the thing about living your full life on
a migratory large mammal like this is that your life
cycle is intrinsically tied to the movements in life cycle
of your host species, that's right, and partially for this reason,
(38:28):
there's so much we don't know about the whale barnacle
life cycle. There's things we don't know about their cycles
and their reproduction. They're just hard to study. So they
seem to mate with other barnacles nearby on the same whale,
but they wait until the whales go to their coastal
breeding and calving grounds to release their larvae. And these
(38:49):
larvae are probably guided by an attraction to a chemical
signal that helps them find the whale skin. This could
be a chemical emitted by other barnacles already present. So
maybe there's kind of a you know, I don't think
korum sensing is the right word. That's from different but
you know, they sense a congregation of their kind, or
it could be a biosignature from the skin of the
(39:11):
whale itself. Maybe they're attracted to some kind of signature
mammalian molecule. They also have to do some crawling around
on the whale as larvae before they cement themselves down,
because you don't just go anywhere on the whale. There
are favored regions of the whale's body, often the forehead,
the tail, and the forward facing edges of the flippers,
(39:34):
and I think this is because it increases their access
to flowing water and the plankton in it. But finally,
there's a really big interesting thread in this article that's
about studying the chemical composition of whale barnacle shells to
determine where whales travel. So barnacles are there, you know,
(39:55):
their shell builders. They are constantly building up new layers
of their calcium carbonate plates, And at some point researchers
figured out that you could look at the layers of
these plates kind of like tree rings, but by analyzing
the ratio of oxygen isotopes in each layer, you couldn't
just tell, you know, it's not just counting the tree rings.
(40:16):
You could actually say a lot about the properties of
the water in which each layer was formed, So what
was the temperature of the water, what was the salinity, etc.
And actually you could then compare that information to things
we know about different regions of the ocean at different times,
and this would allow you, by proxy to roughly track
(40:41):
the migration history of the whale on which a barnacle
lived by peeling back and analyzing the mini layers of
its plates and Researchers initially studied this on the shells
of living or recently living barnacles, but it turns out
you could even do this with fossilized remains of whale barnacles,
(41:01):
and by this method you can track the movements not
only of living whales or recently living whales, but whales
that lived hundreds of thousands of years ago, and that information,
in turn can help shed light on unsolved problems in
whale evolutions, such as when and why did billeen whales
start migrating groombaumb Wrights quote. One hypothesis suggests that it
(41:25):
happened around three million years ago, when massive ice sheets
started spreading across much of the northern hemisphere. The colder
temperatures would have frozen whales out of some of their
habitats and put more constraints on where plankton could flourish
in Earth's oceans, and the patterns that came to exist
in the locations of these, say food and shelter resources,
(41:48):
would therefore lead to the establishment of migration patterns over time.
We don't know exactly how it happened, but that's one idea,
and so it seems like we can now maybe use
fossilized whale barnacles to get some insight into what those
ancient patterns of migration were when they changed, and what
(42:09):
those what those changes might coincide with is, say, in
the climate sphere. And this of course can help shed
light on things today as well. Doesn't just tell us
about the past, because understanding when and why ancient whales
started changing their migratory patterns, for example, in relationship to
ocean temperatures and sea level and so forth, that could
(42:31):
help us understand what's likely to happen in the near
future with oceans being affected by our rapidly heating planet.
So anyway, it was just a few notes from there,
but that article What Whale Barnacles Know very interesting worth
a read. Yeah, yeah, I mean it's it's interesting to
think about. It's easy to dismiss the barnacles. It's just
this hanger on, just this sex up parasite of the whale,
(42:52):
But there's so much information tied up in the barnacle
about the host species. Well, this has been this has
been a really fun journey. I've really enjoyed getting to
dive in to researching the gray whale. After getting to
have this experience with them. I guess some people would
probably do this in reverse order to do their research
and then have the experience, but for whatever reason, I
(43:12):
end up doing it the other way around most of
the time. But I enjoyed I kind of that's one
way to sort of draw out these experiences. Oh, I
don't think it's a bad way at all, experience and
then reflect. Yeah. Yeah. By the way, I've cited several
authors and sources that were helpful in the research for
these episodes, but I'd also like to throw in some
hefty things to the local guides at the Ojo de
(43:33):
Layabre Lagoon, some of which have been doing this sort
of guide work every year for something like thirty five years,
as well as the international tour guides that I had there,
Keith Hassan and Donna in particular. Everyone was delightful and
full of wonderful facts and observations about the whales, and
I also really enjoyed the company of the folks that
my family toured with. In case any of you out
(43:55):
there having to be listening, the great thing about a
trip like this is that no one is that they
are is just kind of sort of into Wales like everyone,
At least in my experience, everyone was really excited, really
into them, and really compassionate for them. So yeah, just
a shout out if should any of you be listening.
All right, we're gonna go ahead and close the book
(44:16):
on this one, but we'll be back with more episodes
next week. Just a reminder that Stuff to Blow Your
Mind is primarily a science podcast, with core episodes publishing
on Tuesdays and Thursdays, but on Mondays we do listener mail.
On Wednesday's a short form artifact or monster fact episode,
and on Fridays we do Weird House Cinema. That's our
time to set aside most serious concerns and just talk
about a strange film. Huge thanks to our audio producer
(44:38):
JJ Poseway. 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, to share something interesting,
or just to say hello, you can email us at
contact at stuff to Blow your Mind dot com. Stuff
(45:00):
to Blow Your Mind is production of iHeartRadio. For more
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