- [Kate] How common are parasites globally?
- [Anai] They're virtually everywhere.
They make up about half or more than half
of our world's biodiversity.
- [Kate] I want to build like a deep appreciation
for parasites, at the same time
as acknowledging that it's like a little bit gross.
(women laughing)
- [Anai] Yeah, but they can be so beautiful.
- [Kate] Welcome to Wavelengths,
where we talk about our planet
with experts from Scripps Institution of Oceanography,
covering everything from the deep sea,
to the edge of the atmosphere.
I'm Kate Furby, a marine biologist and journalist.
I got my PhD here a few years ago,
and now I'm back learning more about what's happening
at Scripps.
(cheery music)
We're here today with Anai Novoa.
She studies parasite ecology.
She's a PhD candidate here at Scripps.
Thanks so much for joining us today.
- Yeah, thanks for having me.
- Can you tell us what a parasite is?
- We have various classifications of parasite.
So a parasite, it has a symbiotic relationship
with the host.
So meaning it lives with it, on it;
it uses the host as a resource.
Sometimes it can be more hurtful than others.
So sometimes for instance,
when we have a tapeworm inside us,
one doesn't do too much damage. A hundred?
We need to get pumped.
- Can you tell me like about how it feels to be in a field
like it's kind of gross,
but it's also like extremely cool and important?
- Parasites are really cool for one reason,
is that they're really good at what they do.
The body of the host is very,
it doesn't want to get infected.
It's doing everything it can
to destroy a parasite intruding its body.
But when the parasite is successful,
'cause some of them are just,
end up going in the wrong host and they die.
But other times when they get in the right host
and they establish there, that is quite spectacular.
- Yeah, like parasites are living in a place
that is literally actively trying to kill them.
We know that climate change, like temperature changes
around the planet, are also moving animals.
Like animals want to live at a certain temperature.
I prefer 75.
And so they're moving to stay within that temperature.
And the question is, which we have no idea,
is like, will the parasites go with the host
or will they struggle to survive and stay behind?
- Yeah, so climate change is affecting where animals
live, breed, and move.
As the planet warms, animals are moving to accommodate
to stay within a certain temperature.
For example, I study a small parasite called a trematode.
It's a small flatworm.
This animal moves through different host bodies
for different phases of its life.
So first, it lives in the marine snail.
Then, in another second intermediate host like a fish.
And then finally, as an adult, it moves into a bird,
but it needs that fish to get eaten by the bird
in order to move bodies.
So it can actually alter the behavior of that fish
to help it get eaten.
(water sloshing)
- Are we worried about
then the parasites finding a different host
and just totally changing the ecosystem that way?
- Yeah.
So we don't know what's happening with these species
that are establishing in their new expanded range.
We don't know what's happening in their southern edge.
Are they still there?
Or how does their abundance look like?
And so we've, in order to better understand
those projections, what the future may look like.
We need to know what it looks like now.
- [Kate] So which parts of the fish
do you find the parasites in?
- [Anai] Everywhere.
I find them in the scales, in the fins, in the gills,
in the eyeball, in the musculature, and in the brain.
- [Kate] Oh my God.
Gross and cool, brain parasites.
It's not ideal.
(Anai laughing)
- [Anai] No.
- [Kate] So it's the ones in the brain though
that changed the behavior.
This feels like a pretty vulnerable time to be a human.
I'm thinking a lot more about
how the world works as a whole.
And it really,
it sounds like the work that you're doing
is really important for us to understand
how things are working and how they might change
going into the future.
- Definitely, parasites are often overlooked in studies
and they are a really important piece
to understanding what's going on in an ecosystem.
And they can also help us better understand
and provide insight into creating predictions
for the coming future.
(calm music)