[♪ and rushing water]
[♪]
Gill Braulik: So, most people are really familiar
with dolphins that live in the sea,
but there are also a number of dolphins that
only live in freshwater, in rivers.
And they're really quite different from the marine dolphins.
The river dolphins that I've spent most of my time working with
are the ones that live in the rivers of South Asia,
so the Indian subcontinent.
And these rivers are huge sediment-laden rivers that are really murky,
so it looks kind of like milk tea.
So, over the course of millions of years,
these dolphins have lost the use of their eyes.
Instead, they use echolocation.
They use clicks and whistles,
and it's incredibly sophisticated,
so they can find fish, they can navigate,
they can feed just using sound.
Dolphins that are in the Indus,
and dolphins in the Ganges,
the river systems are completely separate,
and they've been separate for thousands of years.
So, in the 1970s, they were considered to be different species,
but then in the 90s,
scientists looked again at this information and
decided that it wasn't really strong enough.
And so they changed it, so that they were considered to be the same.
So, at that point, I decided that
I would try and gather the scientific data to answer the question,
are they different or not?
So, initially we started by gathering samples
to do studies of genetics.
And when actually we sat down and lined up the sequences,
it was just so clear that there were really,
really obvious differences.
And then, in order to prove that a species is different,
you really need two lines of evidence.
So, we also needed something like comparing
the shape and size of the skulls,
or comparing the shape and size of the body.
And so, I traveled around different museums
that have skulls from these animals,
as well as in lots of different places in India and Pakistan.
Uzma Khan: So, this association with Gill goes back a long time,
and I remember when she came and then she led
the first thorough survey of the species in 2000.
And that is where I helped Gill in measuring skeletons.
Gill Braulik: And actually, what we found was so unexpected.
Once we really started looking,
there's so many differences between.
And, really, no one had properly looked before.
So, when it came to trying to look up patterns and differences,
I got in touch with Eric Archer,
who's a real specialist on conducting these kinds of statistical studies.
Eric Archer: The NOAA Southwest Fisheries Science Center Lab
has been focused on questions of describing species
and subspecies using genetics for almost 10 years now.
This project was really an international collaboration.
It involved people collecting samples
and analyzing those samples over many years.
And we've been able to compile
the largest amount of data for these two species
that has ever been compiled before.
And that is data on measurements of skulls,
on measurements of the whole body,
that is the length and weight of these animals,
and genetic sequences.
We found that dolphins in these two rivers had
fundamental differences in their DNA,
and the skulls were distinctly different.
Gill Braulik: Indus dolphins have, on average,
five more teeth in their jaws than the Ganges dolphin.
There's really obvious differences in the skulls
that you can see just by sitting them side by side.
Eric Archer: And it was very clear that these are two separate species.
[♪]
Uzma Khan: So, this designation of the
Indus river dolphin as a separate species
will certainly raise the profile of the species.
I think it's very exciting news, and we are all very happy.
I think, one thing that we should acknowledge is that
for both these species, the Ganges and the Indus,
the challenges are enormous.
There are conflicts between communities, over fisheries,
and there are numerous water infrastructure projects that are planned.
Communities are at the heart of any species conservation,
especially in this context, because communities are dependent
on the same habitat as river dolphins are dependent on.
So, we need to work with communities,
to have these species thriving in our rivers,
and thriving in harmony with people.
[clapping]
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