Orcas vs Great White Sharks: How Killer Whales Are Changing Shark Populations

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If orcas keep targeting young, great
white sharks, could they actually

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reshape the future of one of the
ocean's most iconic predators?

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New footage shows orcas hunting
juvenile great white sharks in what

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scientists believes are nursery
zones, the very places where this next

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generation is supposed to grow safely.

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If these attacks become more
common, we're not just watching

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Predator versus predator.

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We might be witnessing a shift
that could ripple through

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the entire marine ecosystem.

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We're gonna talk about all that
on today's episode of the How

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to Protect the Ocean Podcast.

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Let's start the show.

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Hey everybody.

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Welcome back to another exciting episode
of the How to Protect the Ocean Podcast.

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I'm your host, Andrew Lewin, and
this is the podcast where you find

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out what's happening with the ocean,
how you can speak up for the ocean,

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and what you can do to live for
a better ocean by taking action.

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Now, on today's episode, we're gonna
be talking about how orcas in Mexico,

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in Mexican waters are actually
hunting juvenile great white sharks.

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They're predating on a smaller species
going after their livers, and we

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actually have video evidence of that
happening that was published recently

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in Frontiers and Marine Science.

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We're gonna talk about that today.

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But before you do, I want to remind
you if you saw last episode, you

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know that I launched a campaign to
crowdfund the launch of a seagrass

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podcast called the Seagrass Effect.

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Seagrasses are a very important
habitat for marine life.

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They have a high biodiversity index.

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They protect species
from being predated on.

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They protect the security
of the coastline.

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And they sequester carbon.

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They're one of the biggest
habitat to sequester carbon up

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to four times more than forests.

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And we are gonna be talking about that on
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I just need your help in crowdfunding
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This is a place where you can have
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the word out on sea grasses.

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So we're gonna have research, we're
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efforts from all over around the world.

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Please help us out today
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I'd love to hear from you So
let's get back into the episode.

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This looks like another population that
is predating upon great white sharks.

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We've seen this before in South Africa.

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We've seen it potentially in other places,
I think in sort of the northeast Pacific,

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like northwest of the United States.

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And we've seen it happen
where orcas will in a pair

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One of them will grab a great white shark.

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The other one will precisely
go after their liver, make an

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incision, pull out their liver.

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Eat their liver and then they kind
of take turns in it depending on

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where these great white sharks are.

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We've followed port and Starbird, two
orcas that had a pretty big impact on

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the great white shark population in South
Africa, and it's a little controversial

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of whether that's the reason why there
aren't as many great white sharks.

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In specific bays like
Mossel Bay and other places.

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There's a lot of other things at play
at that, but they've definitely had

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an influence in where these great
white sharks are or where they've

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disappeared to in South Africa.

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But now we're starting to see,
and we have video evidence.

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Repeated predation of juvenile great
whites by orcas in Mexican water.

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So the authors of this study that was
in Frontiers in marine science report

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two attack events in the Gulf of
California, August, 2020 and August,

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2022, involving a pod of orcas on
juvenile great white sharks around.

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2.5 meters in length.

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So that's probably, around like the nine
feet, maybe a little bit, maybe a little

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bit less than that rather than the adults
that are going after these juvenile areas.

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Now this adds a new dimension compared
to previous observations, which mostly

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involve adult white sharks, which these
orcas are getting better and better.

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Port starboard have been shown
and observed to actually predate

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upon a great white by themselves.

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It's not in pairs anymore.

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It's by themselves going
after, you know, 20 footers.

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These are big sharks now, these
juveniles are smaller, as we mentioned

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before Now, of course in Mexican waters
they're smaller animals, so you're

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probably seeing one orca on each animal.

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But they're starting to see this happen
obviously on more than one occasion, which

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makes us believe like, Hey, how much is
this happening in these nurseries areas?

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So this is really interesting.

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So.

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The orcas use a method of special
behavior of flipping the young sharks

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upside down inducing tonic immobility.

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When you flip a shark upside down,
it kind of paralyzes them, like

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temporarily immobilizes them.

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And so when they flip them over, they get
uninterrupted access to the shark's liver

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and perhaps other energy rich organs.

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But mostly we know they go for
the liver, which they consume,

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and sometimes sharing it among the
pod members including the calf.

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So it could be a way of teaching
these calfs how to hunt or even how

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to like, get a taste for these livers.

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We know that orcas display interesting
characteristics when they hunt.

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They will put salmon on top of
their heads and ride around with

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salmon on top of their heads.

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We still don't know the reasons
why we think it's more of like

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a celebration of a good hunt.

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We're not sure though completely.

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I know from anecdotal evidence
of people that I've heard from.

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They'll eat moola molars and put the
half the moola moola on their head.

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It's very interesting behavior,
odd behavior, but interesting

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behavior nonetheless.

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And so we know these sharks
go after specialized organs.

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Sometimes brains, sometimes others parts.

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The tongue of blue whales, they like
to go for when they're in Australia.

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And so it's a lot of just different things
that happen, and the way they, they hunt

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and they're very specialized in that.

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But in this way, they flip the
sharks over, they immobilize

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them, they get access to those
organs, especially the liver.

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And then they share among the pod.

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This has been shown before where
they actually will hunt to feed

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other members of their pod.

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It shows a level of intelligence
and heightened awareness, and I

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think that's really interesting.

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Now, of course, the impact images of
the dorsal fin markings and repeated

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behavior point to the same pod of
orcas referred to as the Moctezuma a

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pod, being involved in both events
so that they identify the actual

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pod, so it's the same pod every time.

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The author suggests that this pod
may have a specialization in hunting

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elasmobranchii sharks and rays in
this region beyond typical orca prey.

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So this is not just like they'll go after
marine mammals, they'll go after others.

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They actually try and go
after elasmobranchii Stingrays.

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Flat sharks, what we like to call them,
as well as other sharks like what you

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see, like great whites and so forth.

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So I think that's kind of interesting.

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And then of course, the presence of
juvenile white sharks in this region

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may reflect shifts in the distribution,
attributed in part to warming water

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anomalies such as El Nino events
which could bring young sharks into

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zones where orcas operate regularly.

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So nursery areas for great white
sharks are really still being

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discovered in specific areas.

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We know there's a nursery area in
Southern California along the

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west coast of the United States,
and of course now we're thinking

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that there's a nursery area.

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We don't know the extent of it or if
it stays in one area all the time.

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Just like I mentioned before, El
Nino events and other event warming

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events may shift where these
waters are, depending on their food

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availability for these nurseries.

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Obviously nursery areas are areas that
are gonna be bound with food for these

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great whites so that they can grow and
can go after food that's more their size,

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more their liking, and that'll be great.

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But if it comes in areas where
there are orcas, which we know

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there are in the Gulf of California.

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Then that can actually have
an impact on their population.

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So the authors, they raise concerns
of how predator and prey dynamics may

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change if juveniles are more exposed,
and how this might affect the recruitment

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of great white sharks in the future.

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They already have slow life history.

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So an impact like this where if orcas
can go in and impact like adults in

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Southern Africa where you have those
huge 20 footers, now you're looking

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at an area that we're smaller that are
growing into and that will spread around

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the ocean and show like a population
that's doing well now may be impacted.

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They have slow life history, so if
there's more animals that get impacted

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in terms of get eaten, they're not there
for the next generation to grow, right?

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That generation to grow up into adults,
which will impact their recruitment,

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it'll impact their reproductive ability.

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It'll have lower impact in the future.

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Hence, that's the concern that happens.

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And we just don't know if this
is gonna happen all the time.

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We have no idea if this nursery area
is gonna be in the same place next

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year or the year after, or if it's
still in the same place this year.

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This happened in 2020 and 2022,
which to be honest, is one of the

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problems with peer reviewed papers.

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Although, you wanna make sure
everything is great, it's just the

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writeup, it doesn't happen quick enough.

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Hopefully they're still observing
these areas and the more research

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will be done to see if this
happens over and over again.

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Or if the nursery areas, these sharks
are in the same space, they may

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have left because of that predation.

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The ones that are better off surviving
may have moved into another area based on

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prey, also just based on survivability.

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So we just don't know what's
gonna happen to this population.

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Well, let's be honest, great White
sharks have had a boom in population

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in the United States, on the
East coast and on the west coast.

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We've seen a proliferation
of sharks, even in their

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distribution, has changed as adults.

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We know the Southern California nursery
area, but also adult sharks are going

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as high as San Francisco Bay,
and he may be even higher.

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On the East coast, it used to be Cape
Cod, now they're going up to the Gulf of

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St. Lawrence in that area in Nova Scotia.

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So where they're starting to see
that move, north as the water's warm

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and they still within their range.

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They go out to the Mid-Atlantic bite, they
go all the way down to Florida Cape Cod,

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and now even north into Canadian waters.

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This is going to be a case where
monitoring is still gonna be needed

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for not only these great whites,
but also see what these orcas are

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eating and where they're going and
how the nursery areas are going

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to change based on warming waters.

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You know, it's gonna be a
lot of oceanography, iss

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gonna be a lot of ecology.

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And, see those,
distributions warmer water.

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predator prey kind of relationships,
like the prey for the juvenile.

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Great whites, are they
gonna be in the same area?

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Are they gonna move because of
the shift in warming waters?

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There's a lot to learn from this, but
having these two events definitely shows a

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pattern that may have already been there,
or maybe something new just because the

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orcas are like, Hey, we have new food.

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This is really rich in
nutrients, and we like it, and,

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we're getting a taste for it.

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Now, of course, as they're
getting a taste for it, will

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they follow these sharks along?

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Who knows.

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Will the Sharks population
be affected later on?

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We don't know at this point, but something
that we definitely have to keep an eye on.

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So, looking at nursery areas, looking at
warming, water distribution, looking at

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predator prey distribution and looking at
orca distribution, obviously a predator,

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the apex predator, it seems very, very
smart, and help feeding each other and,

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members of their pod I think is brilliant.

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So we're seeing a lot of really
cool things that are happening out

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in the ocean, but also some scary
things that can happen in the future.

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Now, obviously there's gaps.

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We still don't know how often these
interactions occur, the frequency.

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So how widespread is this behavior
among Orca pods and is that

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happening in elsewhere now that
there are more great white sharks?

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Also it highlights the limitations
of regarding how long juvenile white

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sharks stay in that particular region.

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Their anti predator responses, where
are they gonna go now, as I mentioned

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earlier and how changing ocean
conditions might alter the nursery

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areas, and the predator overlap.

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So we'll see what happens.

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It's a call to action, definitely
to have more systemic monitoring

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of shark nurseries, orca behavior,
and shifting habitat overlap.

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So that's it for today's episode.

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I'd love to hear what
you think about this.

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Do you think these orcas are gonna affect
the great white population in the future?

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Do you think this is just like an anomaly?

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It just happened just because everything
just kind of came to be for these

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orcas and the great white sharks,
that those juveniles just kind of

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came in because they're following prey
and that will change in the future.

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I'd love to hear what you have
to say, and if you're involved in

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any of these studies, let me know.

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I'd love to have more questions for
you, but that's it for today's episode.

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You have any questions or comments,
just let me know in the comments below

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00:10:44,953 --> 00:10:45,763
if you're watching this on YouTube.

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00:10:45,843 --> 00:10:48,243
If you're listening to this in your
favorite podcast app, just hit me up on

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00:10:48,243 --> 00:10:51,543
Instagram at how to protect the Ocean
that's at How to protect the ocean.

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Of course, if you want to go to speak up
for blue.com/contact, you can contact me.

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Just fill out the form.

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00:10:56,913 --> 00:10:57,993
It goes right to my email.

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I'd love to hear from you.

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I wanna thank you so much for
joining me on today's episode of the

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How to Protect the Ocean Podcast.

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I'm your host Andrew Lewin from
the True Nord strong and free.

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Have a great day.

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We'll talk to you next time
and happy conservation.